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Logic's Smart Tempo: Part 1

Apple Logic Pro Tips & Techniques
Published May 2018
By Geoff Smith

Screen 1: In Logic Pro 10.4 it’s easy to record a quick song idea without worrying about tempo. Set the Project Tempo to Adapt, record your idea and then sit back and marvel as Logic automatically changes the Tempo Track to follow the tempo changes in your playing.Screen 1: In Logic Pro 10.4 it’s easy to record a quick song idea without worrying about tempo. Set the Project Tempo to Adapt, record your idea and then sit back and marvel as Logic automatically changes the Tempo Track to follow the tempo changes in your playing.

With Smart Tempo in Logic Pro 10.4, you need no longer record to a click.

In the May 2016 issue (http://sosm.ag/may16logic) we looked at using the iOS app Music Memos to record scratch ideas and then bring them into Logic. The Music Memos app analyses the harmonic and rhythmic content of the recording and then allows you to load it up along with its tempo and harmonic analysis right in Logic. Now, with the Logic 10.4 update, Apple have incorporated the tempo analysis aspect of this technology into a new feature called Smart Tempo.

In this month’s Logic workshop we begin by looking at how the new Smart Tempo features can help you to create a tempo map from a recording of your own playing. We then move on to look at how to take a band recording from a rehearsal and turn it into the perfect tempo map with which to re-record the song. Lastly, we extend the concept to create a tempo map from multitrack stems, to make it easier to work with loops and tempo sync’ed mix plug-ins.

Push The Tempo

In the Control Bar at the top of the interface, the Tempo Display has a new Project Tempo field. This defines the behaviour for Logic’s current Tempo Track when recording, importing or editing audio regions. The Project Tempo has three basic modes of operation:

  • Keep: This is Logic’s legacy tempo behaviour. Typically you set the project tempo and record to it with a metronome.
  • Adapt: Allows a newly recorded, imported or edited audio region to alter the Tempo Track. Use a new recording or import an audio file to create a tempo map for the project.
  • Auto: Uses conditional switching to alternate between Keep and Adapt behaviour. The default behaviour is Adapt unless there’s already a musical reference such as a metronome or audio region in place. In this instance, the behaviour will change to Keep. I personally find it far simpler to change the Project Tempo field between Keep and Adapt rather than trying to remember all the different things that can change the behaviour of the Auto setting.

Improvise, Adapt, Overcome

Let’s look at some examples of how you might use the Smart Tempo feature. Begin by setting the Project Tempo mode to Adapt. When a new recording is made in an empty project, Logic will follow the detected tempo fluctuations of the audio region and alter the project’s Tempo Set accordingly. This frees you from having to set a tempo and a click when inspiration strikes. Create an audio track and record a short song idea. When you’ve finished, Logic will analyse your recording and place beat markers into the audio region. The Tempo Track’s current Tempo Set will then adjust to follow those beat markers. When you finish your recording, Logic will prompt you to ‘Edit Downbeat And Tempo’. Click Show to see the beat markers in the File Tempo Editor. When you are in Adapt mode, Logic automatically opens the Global Tempo Track, which will be colour-coded blue, orange or red. Blue indicates you have a tempo map in this time range. Orange signifies an area yet to be defined by a recording or editing action. Finally, if you copy a recorded region, the Tempo Set will go red to show that the existing Tempo Track area will be replaced or moved.

Now that you have a Tempo Track that follows your recording, you may wish to tweak the tempo of different sections and hear the audio recording adapt to those changes. Let’s use Logic’s real-time time-stretching to hear your edits to the Tempo Set. In the Track parameter area set the Flex Mode to Polyphonic. This will automatically set the region parameter Flex and Follow to On. The Flex and Follow parameter replaces the old Flex parameter from 10.3 with some new options. We can now go to our Tempo Track and edit specific parts or conform it to a single tempo, then instantly hear the result by hitting Play. Once you have settled on your project tempo, the safest thing to do in order to preserve that tempo is to set the Project Tempo Mode back to Keep. This prevents accidental changes to the Tempo Track when new audio is recorded or imported.

Tempo Mapping

Creating a tempo map from a given song has never been easier. In Logic Pro 10.4, you can take a track and extract it’s tempo map in seconds. Let’s look at a simple example. As a rock producer, the typical preparation for recording a less experienced band might involve taking them to a rehearsal room armed with a hand-held recorder. You record a song many times over with the idea that one of those takes will feel right in terms of energy and tempo. You can then select the take that feels the most alive and build your guide track from that, extracting the Tempo Track ready for when you get the band into the studio. In order to do this, open a new Logic project, set the Project Tempo Menu to Adapt and simply drag the rehearsal recording onto an audio track. Logic analyses the tempo map for that rehearsal song and sets the Global Tempo Track to have those tempo fluctuations. Once again set the Flex Mode to Polyphonic and turn on the Flex and Follow behaviour. Go to the Global Tempo Track and click on the Tempo label to reveal the drop-down menu. From that menu choose Duplicate Set. You can now make edits to the tempo map and those edits will time-stretch the rehearsal audio track accordingly. You can also use the Tempo Track drop-down menu to switch between different tempo maps to compare and contrast the end result.

Screen 2: If you duplicate the Tempo Set and then tweak the tempo in the new set you can easily compare and contrast the results of your changes.Screen 2: If you duplicate the Tempo Set and then tweak the tempo in the new set you can easily compare and contrast the results of your changes.

Now, let’s look at a slightly more complicated outcome from our rehearsal room example. You may well be in a scenario where you have a three-minute song in which take one had the best first two minutes, but take three was dynamite in the last minute. In this scenario you would want to combine the two takes to create your tempo map. Open a new Logic project, set the Project Tempo Menu to Adapt and simply drag in take one and then edit the audio region down to two minutes in length. Notice as you reduce the length that the accompanying tempo information in the Tempo Track also gets trimmed to the region length. Now drag take three into the same audio track after take one and trim it to the last minute, again noticing that as you trim off the start of the region, the information is removed from the Tempo Track. Place the first two minutes of take one and last minute of take three next to each other. Note the Tempo Track’s events move with the regions. You should now have a Tempo Track with sections from take one and three analysed and ready to go.

Screen 3: From the File Tempo Editor use the ‘Adapt Project Tempo to Region Tempo and Align to Downbeat’ action to set the Tempo Track from an audio region.Screen 3: From the File Tempo Editor use the ‘Adapt Project Tempo to Region Tempo and Align to Downbeat’ action to set the Tempo Track from an audio region.

Multitrack Madness

To create a tempo map from a set of multitrack stems set the Project Tempo field to Keep and drag in your folder of audio stems. When using multitrack stems to set the Tempo Track you will want them to stay locked together when performing edits. To achieve this, open the Mixer, select all the audio tracks and, from the Group section, assign them to Group 1. Next, right click on one of the group boxes and from the drop-down menu choose Open Group Settings. Within the floating Group Settings window tick the Editing (Selection) option. Now open the File Tempo Editor and select the track that makes the best tempo guide — this is likely to be the kick or overheads from the drum recording. Hit Analyse and wait whilst Logic creates a tempo map. Next, in the File Tempo Editor go to the Actions menu and choose Adapt Project Tempo to Region Tempo and Align to Downbeat (Screen 3). All the tracks in your multitrack should move to align the first downbeat with the bar and add a tempo map.

Having a clearly defined tempo grid makes mixing and editing considerably easier. Now all your markers and playhead movements can fall nicely on the bar and navigation will generally feel easier. When you use time-based effects in the mix you can use the sync options and they will stay in time as the tempo fluctuates. You will also be able to drag in Apple Loops to add percussion and other embellishments to the project knowing they will correctly synchronise with the multitrack.  

Published May 2018