The film of Led Zeppelin's reunion concert was five years in the making — yet Alan Moulder had only three weeks to mix the entire soundtrack!
On December 10, 2007, the three surviving members of Led Zeppelin, aided by drummer Jason Bonham, performed a one-off reunion show at London's O2 Arena. A staggering 20 million people applied for tickets, and 19,000 were there to see Jimmy Page, Robert Plant and John Paul Jones pay tribute to Ahmet Ertegun, the legendary founder of Atlantic Records. And until recently, the only crumbs of compensation for those that weren't there were the numerous bootlegs doing the rounds. According to one estimate, as many as 14,000 people used their mobile phone to record parts of the show, and there was no shortage of professional recording gear in the audience either — one bootleg, the dual-layer A Work In Progress DVD, was professionally edited from 15 camera angles and has PCM sound. However, it wasn't until September 2012 that an official DVD/CD release was announced.
Celebration Day was premièred in cinemas around the world on October 17th, while DVD, Blu-Ray and CD versions were released on November 19, and a triple vinyl LP on December 10, exactly five years after the concert. Reports vary as to why it took so long, but the story goes that a release was not originally planned — the cameras were there to provide visuals for the stage backdrop, but in 2009, director Dick Carruthers presented the band with a rough cut of the visuals, and they were surprised by how great they looked and sounded.
Led Zeppelin were the only act to play a full set at the tribute concert, and the 124-minute long DVD/CD includes many of their best-loved songs: 'Black Dog', 'Dazed And Confused', 'No Quarter', 'Since I've Been Loving You', 'The Song Remains The Same', 'Whole Lotta Love', 'Kashmir' and, of course, 'Stairway To Heaven'. Musically, many of the band's '70s excesses are curtailed, and the songs are shorter and tighter, while Plant gives an intense but dignified performance that does away with the eardrum-piercing shrieks of old, and Page adopts a more textural approach to playing the guitar, with fewer long solos, perhaps because he broke the little finger on his left hand a month before the concert.
Carruthers reportedly spent a whopping 18 months editing Celebration Day, using footage from 16 cameras. This stands in stark contrast to the eleventh-hour, three-week rush to perfect the sound. As was described in SOS's late sister title Performing Musician (www.performing-musician.com/pm/jun08/articles/ledzeppelin.htm), the live sound had been mixed and recorded by 'Big Mick' Hughes and Roy Williams, Plant's regular FOH engineer, who took care of Plant's vocals at the O2. A decent-quality stereo mix had been used during the picture editing, but was not deemed good enough by Jimmy Page, who produced the Celebration Day project. During the Summer of 2012, therefore, a last-minute decision was taken to ask a big-name mixer to remix the audio in stereo and 5.1.
Alan Moulder is known for his work with Nine Inch Nails, Arctic Monkeys, Depeche Mode, Smashing Pumpkins, My Bloody Valentine and the Killers, and he had previously worked with John Paul Jones when he recorded and mixed Them Crooked Vultures' self-titled debut album (2009). But even for this dyed-in-the-wool professional, the call from Page came as a shock. "You could say that it made me leap in the air!” Moulder recalls. "The first contact had been made by Jimmy's management, to make sure I was up for doing it. They also manage Foal and the Big Pink, who I have both worked with, so that may have been why my name came up. As a teenager I had been obsessed with Led Zeppelin, they were my band, so obviously when Jimmy called to say hello, it was a big moment!”
Moulder works from Assault & Battery studios in north-west London, which he co-owns with legendary engineer and producer Flood (U2, New Order, Nine Inch Nails, PJ Harvey), and he conducted the mix sessions for Celebration Day in the studio's mix room, Studio 1. Page regularly visited the studio during the mixing process, though his very first visit didn't exactly go as Moulder would have liked. He recalls, "My assistant, John Catlin, and I had started mixing the opening track of the concert, 'Good Times, Bad Times', at 11am, and Jimmy dropped by at around four that afternoon. When he listened to what we had done, we could tell that he was completely underwhelmed. That really spurred us into action, and it got very late that night! When he came back in the next day, he smiled and said, 'Yes, that's much better!' Jimmy continued to come in every day to listen to what we had done, and he would give his comments, which never were what you would expect. But they were always great comments. He steered the ship. Nobody knows better than he how Led Zeppelin should sound. He immediately knows whether it's right or not, and this could be regarding various aspects, from levels to tone. He really was on top of it.”
Moulder decided to run the whole concert in one enormous 48kHz Pro Tools session, rather than chop things up into individual songs. "The mix that they had was pretty good,” explained Moulder, "so they first asked me to mix just four songs to see if doing it again was worth it. The songs I was initially given were 'Good Times, Bad Times' and 'Ramble On', which were the first two songs of the concert, and 'Since I've Been Loving You' and 'The Song Remains The Same'. Apparently these four tracks were considered problematic, but I was not privy to that fact at the time I first mixed them, so I was not approaching them from that point of view. I started with 'Good Times, Bad Times' and just tried to make that sound as good as possible — this was when Jimmy dropped by the first time. 'Since I've Been Loving You' has keyboards and bass pedals and 'The Song Remains The Same' has the 12-string guitar, and they're both favourites, so perhaps that's why they were picked for the initial try-out.
"Once the decision was taken to go ahead with me mixing the entire project, the main criterion was time. The deadline was August 14th, and it was already July. I was in the middle of crunch time with a Foals record, which I was finishing off, so I had to take a break from that. I also had to go away for a week to work with another band. Plus, both Robert and John Paul were away touring, so their availability to sign off on things was limited. For this reason, flexibility and the ability to recall things and easily make changes were very important. This resulted in me doing a significant part of the work in the box, and in me using stems extensively. I'd done a live album for Depeche Mode many years ago, 101 , and compiling that had been a nightmare, with different bus compression for each track and the crowd sounding different at various points in the set. I had learned from that and decided to do the entire Led Zeppelin concert in one session, so I could press Play at the beginning of the gig and it would run all the way to the end. We have a lot of computer power here, but it was still touch and go whether the computer could handle the entire two-hour session!”
Hughes and Williams had taken no half measures in recording Led Zeppelin. The drums alone were recorded on 21 tracks, with added effects, submix and control tracks taking up another 15 tracks in the final session. There was a DI bass plus two amped tracks: with the bass pedals and various effects, there were a total of 21 bass-related tracks in the final mix. Likewise, the three original guitar tracks (two stereo and one mono) also spawned 21 tracks at the mix, while two stereo keyboard tracks grew to 16 tracks, and there were two Theremin tracks, five Plant vocal tracks and one Jason Bonham vocal track. Finally, four stereo audience tracks expanded to a total of 31. This meant that a session containing about 50 tracks of recorded music ended up at well over 130 tracks with effects, submixes and control tracks.
The availability of the original stereo mix proved to be a major stepping stone, without which it would have been impossible for Moulder to have completed his mix in the allocated time. The prep work done on the session was so complex and extensive that if he'd had to do it all himself, it would probably have taken him several months to mix the entire project. Moreover, as the band have revealed, some aspects of the recording were fixed, for instance in 'Kashmir', during which Plant admitted that he "ran out of steam”. The fixes were done before the session reached Moulder, and other than him adding some drum samples and re-amping the bass, bass pedals and keyboards, no new elements were recorded into the session while he worked on it.
"All the repair work on the session had already been done,” recalls Moulder. "For example, someone had gone through and dipped out all the feedback from the mix with automated EQs, and everything had been trimmed. This was incredibly painstaking editing. The session was in a well-presented state, and everything was recorded exceptionally well and sounded great. The problem with the muddiness in the first couple of songs, I guess, came from the way the sound in the hall changed after the audience came in. Apparently, they could not hear each other very well on stage at that point. But again, it was not something that I deliberately set out to fix. Robert's vocals were also already done, and he had OK'ed the vocal processing that was there. I knew that he liked what was there, and since he was not there to approve any alterations I might make, I mostly worked with what I had. All this saved a lot of time.”
Moulder was not given a specific brief for his mix, which meant that he had remarkably free rein, as long as his work pleased Jimmy Page. "I didn't really have a vision for how I wanted to approach the sound,” explains Moulder, "other than that I tried to make it sound like I imagined it did on the night. Unfortunately, I had not been there, but we also had the FOH board mix, and both mixes gave a pretty good impression. During an initial conversation, the band members told me that they'd had a discussion before the show during which they had decided not to approach things like they had in the '70s, ie. not do the rambling versions of the songs with long solos, but to stick more faithfully to the recordings. You could say that this was a more modern approach. I think I was trying to do the same thing, which was to recreate the feeling of the records that we all know, and make it sound up-to-date in the 21st Century.
"I'd already had a hint of, certainly, John Paul Jones liking to be up-to-date when I worked with Them Crooked Vultures. [Guitarist/singer] Josh Homme had all these ideas about John Paul playing through vintage gear, but when the latter turned up, he had state-of-the-art basses and bass amplifiers with him. Josh asked him whether he didn't want to play through the vintage amplifiers that he had brought, and John said, 'No, I don't! Bass amplifiers in those days were rubbish, and they're much better today, so I'll use these!' John Paul keeps up with everything, and he's a great programmer, and he comes in with a very modern approach. Robert is also very current, and although Jimmy had some vintage gear, the way he puts his sounds together also was not particularly retro.
"In the end, the source material dictated how I went about doing the mix, and this was not only a matter of the sounds, but also the images. We mixed to picture, so we may have subconsciously been affected by the way Dick edited the movie. He mentioned the Shine A Light movie [Martin Scorsese's 2008 Rolling Stones concert film mixed from the camera perspective by Bob Clearmountain, as described in SOS February 2009: /sos/feb09/articles/it_0209.htm], and stressed the idea of making sure that you could hear whatever was in the picture. So if you see Jason hitting a tom, you should be able to hear that. We did do that, though probably a bit more subliminal than in the case of Shine A Light. Unlike for that movie, my CD and DVD stereo mixes are the same. We went a bit more for that idea in the 5.1 mixes — for example, if Jimmy moved across the stage with his guitar, we'd also move the guitar sound slightly across the sound image. But again, I didn't really think about it too much. Having been obsessed with the band in my teenage years, I simply tried to make the material I received sound and feel the way I thought it should to me, as a fan.”
Assault & Battery is graced with a 72-channel SSL G+ 4000-series desk, which is still crucial to Moulder's way of working. "It sounds better, and also… I'm old! It's what I'm used to. It feels right. And I like being able to immediately go to several buttons at once and change things. I bought this desk from Trent Reznor, who had it in his studio in New Orleans, and when I worked on it, I really felt that it had something about it. All desks sound different, and I really like the sound of this one. All the music passed through the desk, but in terms of how I worked, I did rides on the desk for more general 'feel' moves and in the box for detailed things, like picking out the drum hits in 'Good Times, Bad Times'.”
Assault & Battery contains an astonishing amount of outboard, much of it unique or obscure, but Moulder says, "I also use plug-ins a lot. I think it's all good. One reason I like plug-ins is that you can automate them. But I also run many things through analogue outboard, even if it's not doing very much. I'll have a Manley Vari-Mu on the mix bus, and the meter won't be moving, but it has valves and transformers in it, so it will be adding something to a sound, however little. All the things I use do something to make the sound a tiny bit better, and if you add everything together, the end result will be a lot better. It's the kind of philosophy I'm working with. It's simple: better is better, whether it's a tiny bit better or a lot better. But sometimes you do something to a track and it does not sound better, and it can be hard to find out why. It's one of the reasons why I'm not one of the quickest, because there's no science to what I do. I am just stumbling around until I find something. I try to take a different approach with each project, and take it to a point where I think it's not too bad, and I then keep chipping away at it to see what I can improve. But especially in the beginning I can be slow, when I'm finding out how to deal with things and what the whole project is about. That was the case that first day when Jimmy walked in. I had only just begun!”
Unlike some mix engineers, Moulder likes to take rough mixes as a point of departure, and he felt that was especially important in this case. "Normally John [Catlin] will prepare the session for me, and will set it up so it is close to the rough mix, balance-wise, and I'll then begin with listening to that. In this case, I obviously had both the FOH mix and the existing mix as orientation points. The rough mix is important to me, because it gives me a starting point. It's how the band and the producer have been hearing the song, and I try to take that vision further, rather than just do what I think needs to be done. The job of a mixer these days often involves what can be seen as additional production, but it tends to be invisible: I may add things that they may not even notice. It's rare for me to make major changes unless they are agreed beforehand. I will first try to make work what's there. Whatever way, my aim is to achieve what I understand to be their vision. Once I'm clear on this and on what I have, I will break the mix down. Generally I'll start with the bottom end, ie. the drums and then the bass, and then move upwards.
"Again, we treated the whole session as one to make sure that every song flowed into the next song and the audience was consistent all the way through. Rather than spend a long time on individual songs, we kept going through the entire concert as fast as we could and then we'd start again. We'd maybe work on one song for three or four hours, and then we'd move to the next song, and in doing so worked in blocks of three or four songs per day, until we came to the end, and then we went back to the beginning. We learned something new every time we listened. But you get fatigued and your attention goes, so we regularly had to take breaks. It took time for us to get a flow, and it was a very different approach to mixing individual songs.
"As I said before, the session was extremely well-presented, with everything grouped and trimmed and in many cases treated with EQ and compression. As a rule, I didn't change the trimming, EQ and compression that were already in the mix. I also set my own EQ and compression and effects for the entire session, and then made adjustments for each individual song, though a lot of these involved simply changing levels. The effects returns on the SSL are pretty much hard-wired, and I would have used a selection of them. On the left side are the Elysia compressor, Fatso Jr tape simulator and compressor, Neve 33609 compressor, Ridge Farm Boiler compressor, Distressor, Dbx 160 compressor, AMS DMX150s delay, Eventide 2016 and H3500 effect units, and EMT plate reverb, and on the right the Drawmer compressor, Valley People Dynamite compressor, Marshall Time Modulator which is an '80s short delay and phaser, Delta Lab Effectron which is a very old digital delay, Thermionic Culture Vulture, Dbx 120 [subharmonic synthesizer] and Eventide H910 Harmonizer.”
Drums: NI Battery, Waves Renaissance Bass, Avid Reverb One, Valhalla Room, IK Classik Reverb, Elysia Mpressor, Empirical Labs Fatso and Distressor, Neve 33609, Dbx 160 and 120, Valley People Dynamite, Drawmer DS201.
"Jason had the hardest job of the night. Number one, he's filling in for his father, who was one of the greatest drummers ever and certainly everyone's favourite drummer, and so all eyes in the audience were on him. Plus he had to play many very intricate drum parts, particularly so in 'Good Times Bad Times'. So I felt obliged to give him the best I could and pull everything possible out of what he played. The drums were separated out into two kick tracks, two snares, separate tom tracks, two sets of overheads, ride, hi-hat, and there were some timpani and gong overdubs. All the trimming had been done, but the first thing we did, again particularly on 'Good Times Bad Times', was to scoop out his playing from the general muddiness. We did this by using volume automation in the box. There wasn't an individual mic for the cowbell, for example, so it was tricky to pick that out without increasing the muddiness, and the two tom tracks also needed detailed pulling out of the hits. On 'Ramble On', I split the toms into different sections and EQ'ed them differently for different parts of the song. We also spent time picking out the hi-hats a bit.
"John added samples to beef up the kick and snare with a Native Instruments Battery 3 cell. The great thing about that is that you can put any sample in, with any sample rate, and it works it out. We use a MIDI map, and we can write the velocities in so the samples follow the actual drum recordings sympathetically. The reason we added these samples was for extra clarity and to add low-end weight on the kick drum, and also to add a little bit more body to the snare. The sample sounds we picked remained the same for the entire session. The samples were there to enhance the original sounds, to fill in any holes in the spectrum that were missing, not to replace them. I sent the two kick-mic tracks to a kick submix track and added a Waves Renaissance Bass plug-in for some low harmonics, to give it some beef. I had the Battery cell on another track, and all the sample kick sounds went to yet another track, and the live and sample kicks came up on different channels on the board, where I balanced them. It was the same with the snare tracks.
"I had also set up some drum reverb plug-ins, the Reverb One, the Valhalla Room, and the IK Multimedia Classik CSR Hall reverb, set to 'drums medium hall'. I really like the sound of the IK CSR reverbs, they sound a bit like the old AMS RMX16, with a big, deluxe feel. I used the Reverb One and Valhalla Room on the kick and snare and also the tom sub. The Valhalla Room is a great plug-in, and it seemed strangely correct to use a plug-in with that name on a Led Zeppelin album! On some songs, the drums reverbs were automated to give the kicks big, explosive reverbs. It was similar with the timpani, which I put through the CSR big reverb, because you want it to sound quite grandiose. I also had additional reverb on the snare, to give it a bit of depth and make it sit in the track. It was more like a colour on an individual sound and to give it its own pocket. I had the room up quite loud in the mix throughout the concert, it was well-recorded and it provided a lot of the general reverb and ambience. The use of plug-in and outboard reverbs in this project was purely to glue the on-stage sound together with the sound of the audience. Sometimes things would start to sound a little separated, and small amounts of additional reverb seemed to blend everything together again.
"I did a lot of the more general 'feel' rides on the drums on the desk. I EQ'ed the channels and then did parallel compression on the desk using various compressors — the Elysia, the Fatso, the 33609, the Dbx 160, and sometimes the Distressor or the Dynamite, another old compressor/limiter, all set to taste. I use the Elysia a lot, I love it. I also used that on the overheads. Plus I had the kick and snare up on two other channels on the desk as well, gated through the Drawmers, to get a tight sound, EQ'ed and compressed severely, and then sent to a Dbx 120 sub-compressor to get more low end in, but very controlled because it is gated. I may have brought the Elysia up in the choruses, to give the drums a little bit more of a lift. Drummers play many grace notes on the snare drum these days, and I always try and pick out what they are playing, because you often don't hear that. When he is playing subtle grace notes in the verse, you can bring those out with the compressor, and when it goes to the chorus where he is hitting harder, you just mute it. In this way you can help bring out nuances and the articulation of the drum playing.”
Bass guitar and pedals: Waves Renaissance Bass, Vox, EQ and SSL Channel, Ridge Farm Boiler, Sound Toys Filter Freak and Decapitator, Trillium Lane TL Space, desk EQ, AMS DMX.
"There were quite a few bass guitar tracks, with a DI track, and a clean [SWR] amp and a Black Cat, which was the more distorted-sounding. They all went through a submix track, on which I had the RBass and the RVox to maintain consistency. I automated these plug-ins: the RBass just enters in certain places where the bottom end disappears. As with many tracks in the session, there's also EQ and SSL Channel. I also used some Boiler outboard compression on the bass. I re-amped the DI, to bring out some harmonics, so as to add tonality, using my Audio Kitchen amplifier. I have one here that was especially built for me, commissioned by Flood and my wife for my birthday. It's incredibly versatile, very, very quiet, and the controls are very simple: gain, volume, bass and treble, and then there's the way the valves work, with options like low boost, flat and high boost, and you can also go for a more driven gain sound. I record it with a Neumann U47 FET. I added the Audio Kitchen sound to what I already had in the session. The bass pedal was also DI'ed, and so I re-amped that through the Audio Kitchen, adding some RBass, RVox and also Sound Toys Filter Freak and Decapitator, plus the same Trillium Lane reverb that I used on the guitars, to make it feel right. On the desk it was just EQ and I used some AMS harmonizer as well. You're dealing with a DI, and you want to make it sound like a hurricane going through the PA.”
"There were two double tracks and a mono guitar track. The latter may have contained some of the fixes, like on 'In My Time Of Dying', Jimmy's high 'E' string had gotten stuck under one of the screws on his pick-up and that was causing problems. He did not make a big thing of the finger problem, by the way, even though it meant that he certainly had to reach within himself to pull out something special. He did that brilliantly. The double tracks were just different mics on Jimmy's live rig [a 30W Orange head on a 4x12 cabinet, also going into Engl and Marshall stacks], and I added automated plug-in EQs on several of the tracks. Sometimes these EQs were simply bypassed. I also used the Waves Spreader, and the Trillium Lane TL Space for reverb, and sometimes I put some slap delays on his solos, using the Sound Toys Echo Boy or the Waves H-Delay, to give the solos a different space and push them a bit more to the front. The main piece of outboard I used on the guitars was the Helios Type 69 EQ, which had the same setting for the entire concert. I didn't really add compression to the guitars, though I did engage the SSL channel compressor, just because I like to run things through it. It seems to give things a bit more body. The 12-string had the Cranesong Dark Essence to give it some analogue-like glue and add some harmonics. I had a different Helios setting for the 12-string, to add more zing.”
Keyboards: Trillium Lane TL Space, Bomb Factory BF76, desk EQ, RSS Surround.
"The keyboard tracks consisted of two stereo DI signals that, on the night, went through a massive PA system, making them sound considerably different than when you just put the DIs up. So we mixed the keyboards to stereo and re-amped them, first going through two Audio Kitchen Big Tree pedals and then into the Audio Kitchen speaker cabinet, recorded with the ribbon Sontronics Delta mics, which are fantastic. In the box there was some reverb from the TL Space, so we could automate it, and compression from the Bomb Factory 1176. The rest was just desk EQ and balancing. We put Jimmy's Theremin through the RSS surround to give it some 3D in stereo and then panned it around manually so it moved in the stereo spectrum.”
Vocals: EMT 140, Waves H-Delay, Renaissance Vox and De-esser, desk EQ, Line 6 Echo Farm.
"As I mentioned before, I'd been given vocals that had been approved by Robert. These consisted of five tracks that he liked the sound of, so I used those and balanced within them. I just folded them down to stereo. On top of this, I would add occasional things, like some plate reverb and the occasional slap from the Waves H-Delay. Robert's harmonica was recorded with his vocal mic, and just required some EQ adjustments. Jason's vocal was rather challenging to deal with. His singing was great, but there was a lot of spill from the drums. So that involved a lot of automated EQ'ing. I also had some Echo Farm, RVox and a de-esser plug-in on him.”
Stereo mix: Vac Rac 4000, Manley Vari-Mu, Dramastic Obsidian, GML 8200.
"We recorded back into the [Pro Tools] session for the stereo mix, via the Lavry Gold A-D converter. I had the Inward Connection 'Knob', as we call it, to attenuate the level, and then the Vac Rac 4000 valve EQ. I love the tone you get from it. It's a notch EQ, so you can't be particularly delicate with it, but it is probably my favourite-sounding EQ. After that, the Manley Vari-Mu to add some nice harmonics but not for the compression, and then the Dramastic Audio Obsidian TX10, which is my main bus compressor, and finally the GML 8200 EQ. The stereo mix was mastered by John Davis at Metropolis. I tend not to limit my mixes when I send them off, and hope that the mastering doesn't take it to the limit either. The reason people don't buy music any more is that it is so screaming at you that you'd rather keep it arm's length. Most things today sound loud and instantly impressionable, but just two-dimensional, whereas if you listen to music from the 1970s, you marvel at the depth and clarity of the sound. Obviously, I tried to retain that depth and clarity in my mix while still making Led Zeppelin sound modern.”
Judging from the gushing reactions to Celebration Day, Moulder succeeded admirably...
Even after Alan Moulder had finished the stereo mixes of Celebration Day, there remained the small matter of extending them into the surround realm. "While I was away in New York, working with the Killers, John [Catlin] set up a 5.1 mix in the anteroom that's part of studio 1. He printed stereo stems — kick, snare, kit, bass guitar, bass pedals, two different guitars, keyboards, vocals, Theremin — and got the balance to feel the same as in stereo. He panned the audience tracks in the same position as where the mics had been in the hall and the band in the front. From there we went through the session again, and did any rides to make sure everything was coming through and corresponded with the visuals. When listening to 5.1, I like to be reminded that I do have rear speakers — otherwise why bother? — so we did pan some of the music around as well, like guitar and keyboard delays and reverbs, to give it some more depth. We again treated the entire concert as one session, going methodically through it, and starting again at the beginning once we reached the end.”
Alan Moulder explains that the audience mics were vital to retaining the feel of a live show. "I could not have done this without all the automated EQ that was already in the session that took out the feedback. I grouped all the audience tracks together and simply set the crowd at a certain level on the desk, and did not move the faders after that, other than riding them a little at the beginning and end of the songs, so you get the swell of the excitement of the audience. But I made sure that I always brought the fader back to the marked point. The audience tracks provided much of the ambience for the entire concert. Any other adjustments, levels and EQ, were done in the box.”