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Remixing Techniques In Logic

Logic Tips & Techniques By Andrea Pejrolo
Published September 2006

Everything you need to know to create precise and original remixes!

Apple's Logic Pro is packed with features that are specifically targeted at remixers, but sometimes those features are somewhat 'hidden under the hood', so let's take a look at them and learn some tricks that will help bring your remixes to another level.

In the lower part of the Beat Mapping lane you can see the hitpoints representing the detected transients.In the lower part of the Beat Mapping lane you can see the hitpoints representing the detected transients.

Beat Mapping

In order to get started with remixing a track, you need to have the tempo of your sequence perfectly in sync with the tempo of the original song. This task is somewhat easier if you are remixing a track that was originally recorded to a click track and that was sequencer-based, but don't assume that if your original track fulfils these requirements you are up for a smooth ride. Very often, even if a song was sequenced and locked to a click track, the composer/producer might have sneaked in some slight tempo changes in order to spice up the groove of the song. This translates into not being able to use a single steady tempo change at the beginning of your remix sequence, since later in the piece that tempo might not work.

It is even harder to do a remix of a track that was not played to a click track — a jazz track or a tune from the '50s or '60s, for example, can be extremely tricky to remix, because of the natural tempo fluctuations that are embedded in it. Fortunately Logic comes to the rescue with an extremely flexible tool called Beat Mapping, which allows the sequencer to flexibly adapt and recalculate the time that separates each bar and beat of an audio track. Usually you will have a steady tempo between bars and beats, but often your live performances won't follow this rule. With Beat Mapping you can graphically adapt the positions of the bars and beats of the tempo map of your sequence to match the ones of pre-existing audio or MIDI tracks.

Beat Mapping is available directly from the main Arrange window. To map the tempo track of the piece that you want to remix, first import the audio material into an empty audio track. Zoom in to a comfortable setting in the Arrange window so that you can easily see the main downbeat transients of the waveform. Now select Beat Mapping from the View menu's Global Track Components submenu. A new Global Track will appear at the top of the Arrange window. Before using Beat Mapping I recommend trimming and moving the audio material in order to line up the first downbeat with the beginning of the sequence.

Now is the time to let Logic analyse the waveform of the audio material you want to remix. To do this, select the audio object you want to analyse in the Arrange window, and then click on the Analyse button from the Beat Mapping track. This action allows Logic to detect the transients of the selected audio file and mark them in the lower part of the Beat Mapping track.

If you want to change the sensitivity of the beat detection, use the Detection Sensitivity option located in the Beat Mapping track. A medium setting usually works for the majority of audio material, but if the amplitude of the audio material is fairly low, a high setting will give you more accurate results.

Once the transients have been identified, it is time to align the bars and beats of the sequencer's tempo track to the transients in your audio material. The concept behind this action is that we are stretching our tempo tracks to fit the tempo track of the original audio material we are remixing. Simply drag the beats in the upper part of the Beat Mapping track to match the ones in the lower part. It is enough to move the bars and beats of the tempo map slightly, since they will automatically snap to the closest transient once moved.

For every adaptation of the bars and beats, a new tempo change will be inserted automatically by Logic to accommodate the changes you made. A good rule of thumb is to start with an overall tempo that is fairly close to the tempo of the track you are remixing. This will keep the movements of the beats to a minimum, and it will save you time.

If you are planning to remix an entire song, use the Beat Mapping feature to map the tempo track of the entire tune. Being as accurate as possible during this process will save you time later. Keep in mind that while this process might seem tedious at the beginning, it will come in handy later during the creative stage of the remix process, since it will make editing the original audio material a breeze. The audio track is now locked to the tempo track, which means that all the edits can now be done with the Snap To Grid options on. Cutting and pasting audio has never been easier! Once you have done all the necessary preparatory work it is now time to start adding elements to your remix.

Logic News

Apple have released Logic v7.2.1, but you may not have noticed if you use Software Update to check for the latest versions. Apple had labelled the update for Express only, thus keeping many Pro users completely in the dark. Even if you religiously use Software Update to check for new releases, it's still useful to occasionally have a look at the Logic area on www.apple.com/uk, as there is often other useful stuff there, such as interviews and technique articles. Version 7.2.1 is basically a bug-fix with a few extras thrown in for good measure. Unfortunately, it still doesn't support quad-processor G5s, and a few of my colleagues who are using these Macs are living in a state of nervous anticipation of each new update. However, as many of them are using Apple's video-editing packages, which can use all four processors, it's not all bad news for those owners of this beast of a computer.

The good news is that the annoying bug that sometimes caused a blank Sample Edit window to open if you double-clicked on an audio file seems to have been fixed, along with Logic 's tendency to stop delivering any sound from virtual instruments at seemingly random intervals. There have been some improvements for those using Intel processor Macs too, in Rewire and Recycle support, MIDI file and OMF export, and various other small changes. Assuming you have managed to download the maintenance release, you'll also have to use the new version of the Logic Node program if you need it. Version 7.2.1 seems a little zippier on my G5, and the annoying crashes I often get when exiting Logic seem to have finally disappeared. The update notes are available from www.apple.com/support/downloads/logicproupdate721.html and there's finally a enhancement/bug-fix list for the latest Logic versions at www.apple.com/support/logic.

Other improvements in v7.2.1 mainly concern control-surface support. Apple have made great strides in this area since Logic version 7 was introduced, by directly supporting several manufacturers' devices, and the compatibility list is now pretty extensive. You no longer need to spend time assigning controllers and wondering why when you're twiddling your pan knob the filter cutoff changes instead. There is now EuCon support for the high-end Euphonix consoles, along with some improvements to currently supported hardware. I was lucky enough to use a SmartAV Elite series console in combination with Logic the other week, and I was very impressed with the integration — though these controllers come at a pretty high price!

At the other end of the scale, I checked out a colleague's M-Audio iControl, which he uses with Garage Band (for which it was specifically designed). Logic automatically detected that I was using the iControl and I was happily clicking and twiddling in no time. While this unit is a little under-specified for Logic, it shows that you don't need to spend a lot to get your hands on some physical controls. Many people have been using the Logic/Mackie Control surfaces for many years now, but there's a whole range of alternative (and cheaper) devices Logic can use 'out of the box'. There's a full list and a user guide PDF of Logic 's 'native' support for control surfaces at http://manuals.info.apple.com/en/Logic _Pro_Control_Surfaces_Support.pdf.

I still feel that it's at the mixing stage where hardware controls really come into their own — it's hard for a physical unit to combine the extensive visual display of the parameters of a plug-in using a box full of faders, LEDs, and knobs. But if you've been put off in the past from using a control surface because of their apparent complexity, perhaps it's time to dip your feet in the water again. Stephen Bennett

Incorporating Your Own Loops

A big part of a remix project, usually, is the addition of loop-based material such as drum loops, riffs, and so on. This technique has become a basic component of a wide range of remix techniques adopted by the majority of the producers. The addition of a drum loop can instantly add some extra punch and groove to a remix. In Logic there are two main ways to add loop-based material to a project: you can use either regular loops or Apple Loops. The former type of loop needs to be imported and its tempo adjusted by applying time-stretching algorithms in order to have the loop and the original audio material of the remix match. The latter type is a special type of loop that is able automatically to adapt to the tempo map of a project without requiring any extra work from your side. Let's take a look at how Logic handles loop-based material and how to make our loops play nicely with a pre-existing tempo map.

The Apple Loop Browser allows you to quickly preview and access hundreds of bundled loops.The Apple Loop Browser allows you to quickly preview and access hundreds of bundled loops.To match the tempo of an imported loop with that of the sequencer, first put the loop you want to use into an empty audio track of the Arrange window of your remix project. Then make sure that your loop is trimmed to an exact number of bars (usually two, four, or eight). If necessary, fine-tune the beginning and end of the audio object. Move the beginning of the loop object to the beginning of the bar where you want to have your loop played. Now select the loop object and, in the timeline area of the Arrange window, select the same number of bars the loop is made of.

Once Logic knows the loop object you want to time-stretch and the length of the loop in bars, select Adjust Region Length By Locators from the Audio menu. Logic will now perform the necessary time-stretching calculations to change the tempo of the loop and to have it match the tempo of the project.

The final audio quality of the time-stretching operation highly depends on the type of audio material in the loop and on the time-stretching algorithm chosen. You can change the default algorithm by choosing one of the options from the Audio menu's Time Machine Algorithm submenu. Keep in mind, though, that this technique works only when used in a project that has a steady tempo map for at least the duration of the loop. This means that no tempo changes should be present inside the bar range of the loop. If, for example, inside the loop range there is a rallentando, a regular loop won't automatically adjust itself to follow smooth tempo changes — for this you need Apple Loops.

Beat Mapping With MIDI Regions

You can achieve tempo matching with MIDI parts by selecting the MIDI sequence that contains your MIDI performance and selecting the Beats From Region option from the Beat Mapping component track. This function is great because it allows you to pre-conduct your sequencer — simply record a single-note click track from your MIDI controller, doing any accelerandos and rallentandos required, and then select the region containing your new click track as the source for the Beats From Region function.

Using Apple Loops

The basic idea behind the Apple Loop concept is to make audio loops as flexible as possible in terms of tempo. Logic comes bundled with a comprehensive series of Apple Loops, and these are accessible through the Apple Loop Browser, accessible from the Loop Browser option in the Apple menu.

To use an Apple Loop in your remix, simply open the Apple Loop Browser, select the category that you want to browse, and select the loop you want to preview. When you find the one you like, simply drag it to an empty track in the Arrange window of your project. Since these are Apple Loops, they will automatically adapt to the tempo map of your project, and they will also follow any tempo changes that you previously inserted.

While a regular audio loop has only one anchor point available (usually located at the beginning of the audio region), an Apple Loop has a series of anchor points (referred to as hitpoints) inside the region, each associated with an event inside the loop. These events represent the transients of the audio material contained in the loop. In a drum loop, for example, each transient represents a single hit of the bass drum, the snare, the hi-hat, and so on. Each hitpoint behaves, in the sequencer, as an independent entity, and it is anchored, much like a MIDI event, to bars and beats and not to real time.

Whenever you change the tempo of your sequencer, the loop (and its hitpoints) will automatically adjust according to the new bars/beats position. A built-in and automatic time-stretch/compression engine guarantees a smooth transition between slices when the tempo of the project doesn't match the original tempo of the loop. This format also has the advantage of allowing you to change tempo continuously without having to readjust the tempo of each audio loop manually.

Remix Ready!

Logic offers an amazing set of tools to create precise and original remixes in a matter of hours. All that leaves you to do is select a track to remix, and get inspired! 

Creating Your Own Apple Loops

A loop opened using the Apple Loop Utility. Notice the hitpoints that were identified and associated with each transient of the loop.A loop opened using the Apple Loop Utility. Notice the hitpoints that were identified and associated with each transient of the loop. To convert a regular loop into an Apple Loop is very simple and it doesn't require any extra application. When you install Logic in your computer, the installer automatically loads Apple Loop Utility. This application can be launched directly from Logic by first selecting an audio region in the Arrange window, trimming the start and end to a precise downbeat, and then choosing Open In Apple Loop Utility from the audio menu. If the tempo of the loop doesn't match the current tempo of your project, you will be prompted with a window asking you to specify the number of bars the loop is made of.

Click the Use Set Length button, and you will then be presented with the loop Tags window. Here is where you can add cataloguing information about the loop you are converting. All this information will be useful when you are browsing the loops library from the Apple Loop Browser inside Logic. You can preview your loop by using the transport buttons at the bottom of the window.

To edit hitpoints inside the loop, select the Transients tab at the top of the window. Here you can quickly adjust the number of slices by using the Transient Division located at the top of this window. Choose the basic rhythmic subdivision your loop is based on (1/8th notes, 1/16th notes, and so on). Use the Sensitivity slider to choose the number of hitpoints based on the amplitude of the transients present in the loop. You can easily edit the position of single hitpoints by dragging the blue handles at the top of each slice. If you want to delete a hitpoint, simply grab its handle and drag it down. To insert a hitpoint, click on an empty space between two handles. Save the new Apple Loop by clicking on the Save button in the lower right-hand corner. Now when you go back to the Arrange window of your project you will notice that the loop will automatically adapt to the current tempo.