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By Jim Batcho
Aug 1, 2006

Ever since the soft-synth/sampler revolution began toward the end of the last millennium, Digidesign Pro Tools has attempted a variety of methods to exploit it in the world's most celebrated music application. The DirectConnect and SampleCell experiments are long gone, but there is something new to Pro Tools 7 that won't be going anywhere because it's built right into the application: Instrument tracks.

The reason the Instrument track is such an important breakthrough? Simplicity. If you fear MIDI or have been frustrated in the past by issues such as patch management and cumbersome signal routing, your fears have been alleviated. Another great thing about Instrument tracks is their flexibility. Instrument tracks not only allow easy use of software instruments, but they also allow better integration of hardware devices while seamlessly incorporating the new MIDI features in Pro Tools 7. This article looks specifically at how to take advantage of the capabilities of Instrument tracks in Pro Tools LE and M-Powered 7 or later to power your software instruments.

In essence, an Instrument track combines the flexibility of MIDI with all the benefits of the Pro Tools mixing and automation engine in a single channel strip. Put even more simply, an Instrument track is a combined MIDI and auxiliary input track. The idea is to use the benefits of both and make creative compositional work much more intuitive than with the previous iterations of Pro Tools. In Pro Tools 5 and 6, you'd route a MIDI track to an aux, set your channel assignment and hope everything communicated nicely. This new method is far more straightforward because you work with MIDI in much the same way you use a standard RTAS plug-in. That has several obvious benefits. In a live setting, you can use a laptop and a Digidesign Mbox, Digi 002 or any M-Audio M-Powered interface with a MIDI controller as a performance system by playing your soft synths through Pro Tools. In the studio, you can record those instruments as easily as you might record any audio source. And because an Instrument track records MIDI data but functions in an audio fashion, you also have the ability not only to change MIDI notes and associated data after the fact, but also to automate plug-in parameters within the Instrument track just as you would any other plug-in. You can take advantage of the Pro Tools mixing architecture by routing Instrument tracks to auxiliary channels, creating effects loops and grouping particular instruments to discrete submixes. When you consider that LE 7 supports 32 Instrument tracks and as many as 10 sends per channel, there's a lot of opportunity for experimentation.

For this article, I worked with Pro Tools LE 7.1 through a Digi 002 on a Mac dual 1.8GHz G5 with 1 GB of RAM. I concentrated on three software instruments: Digidesign Hybrid high-definition software synth, which is included in the Music Production Toolkit (see sidebar); Native Instruments Battery 2 virtual drum module; and Cakewalk Rapture wave-table synthesizer. Each one worked flawlessly and sounded phenomenal, and together they made for a very complementary system of options.

Using Instrument tracks is simple. Create a new track and select Instrument Track from the Track Options menu. You're given what looks like a MIDI track, except that it has inserts, sends and other channel settings you'll find on an aux channel and a host of new viewing options for MIDI data. Choosing View > Mix Window > Instruments shows the instrument settings at the very top of the channel strip, including channel, instrument, volume, pan, mute and MIDI activity. In the Edit window, another new viewing option is “real-time properties,” which works for both instrument tracks and normal MIDI tracks. Real-time properties are new to Pro Tools 7 and offer a way of changing quantization, duration, delay, velocity and transpose in real time during playback. Quantizing grooves has never been easier. (Incidentally, there are many other new MIDI features in version 7.1 that go beyond the scope of this article.)

To bring in an instrument of choice, simply instantiate it as an insert from the channel strip the same way you'd select a plug-in. Pro Tools automatically routes the MIDI channel output assignments. You don't even need to record-enable the instrument in order to play it (again, a nice feature for laptop performers). Auditioning multiple instruments on multiple tracks is handled intuitively. Whichever track you have selected (highlighted) is the track that your controller triggers. That makes it easy to move around multiple instruments in a single session and is also beneficial for easily doing overdubs. Recording an Instrument track works the same as any other Pro Tools track type: Record-enable the track and press Command + Spacebar.

Recording a performance to an Instrument track, however, is only the beginning. Because your instruments are plug-ins, you can swap out different patches, save and recall presets and even change instruments entirely. For example, with Battery you can customize your own kits and save them as new files. If you save several files using the same note placements on your controller, you can easily swap out different kits for a performance you've already recorded as MIDI data. Instrument tracks also support mix and edit groups, which allow for a number of different possibilities. Using Battery or some other drum-programming software, you could develop a full kit among discrete tracks, place them in a mix group and then mix them against other elements in the same way you would a recording of an acoustic kit. That method also allows you to instantiate third-party compressors and EQs, not to mention setting different send levels for reverbs and the like.

The automation capabilities within Instrument tracks encompass both MIDI and audio playlist data. You have MIDI volume, pan and mute controller events, as well as standard mixer-based automation for volume, pan, mute, buses and RTAS plug-in parameters. That last bit is worth highlighting because your instrument is, of course, an RTAS plug-in. It should be noted, however, that the automation capabilities are slightly different for instruments than for other types of plug-ins. Namely, you can't use the Control + Option + Command keys to enable automation for an LFO depth knob, for example. You can write automation from within the plug-in window just as any other plug-in type, but it would be better to have the keyboard shortcut available, particularly because there is a staggering amount of automation controls available in these plug-ins. It's sometimes difficult to know which parameter you're enabling without having the ability to select it directly within the interface.

With Instrument tracks, you can easily go a little nuts with the possibilities. The only major inhibitor is that same old story: CPU limitations. If you're used to working in Pro Tools, chances are you do a lot of routing of audio tracks for submixing and creating effects loops. Because Instrument tracks behave so similarly to audio tracks, it's easy to forget that the tracks themselves are not audio signals; they're software plug-ins. So management of scarce resources is an important part of working with Instrument tracks. Truthfully, I was surprised that there were times when I had 11 instruments running simultaneously. But other times it took only eight running to activate the operating-system-interrupts warning. Adding to the system drain, to really take advantage of Instrument tracks, you'll want to instantiate additional plug-ins on inserts and send out buses to different effects. The topic of system resources is always subjective, but the fact remains that on slower computers, you'll have to find methods of compensating for the brick walls you'll inevitably hit. Thankfully, Instrument tracks support Pro Tools' active and inactive track states. By Control + Command + clicking on the small piano track icon at the bottom of a channel strip, you make the track inactive. That temporarily removes the track (as well as any plug-ins it uses) from the session and keeps it from draining processor power.

The best way to work with Instrument tracks is to create a session with one Instrument track for each software instrument you use and instantiate each instrument on the first insert of each track. In my sessions, Battery is the first track for the rhythm. Rapture comes second because I absolutely love the flavor, quality and variety of bass lines it generates, not to mention its various methods for creating intricate textures and ambiences. Finally, Hybrid is third for creating additional pads and step-sequencer patterns. After each Instrument track, create an associated audio track for it. For example, my “Battery 1” Instrument track has “BtryAudio” sitting next to it. The idea is to have an audio track ready for when you want to record the instrument performance to disk.

Next, set output assignments so they're ready to record to disk and so you can monitor your work. To do that, set each Instrument track's output to a bus that corresponds to the input on the audio track. That will enable you to record your Instrument track to its audio track. To monitor your Instrument tracks, hold down the Control key (Mac) and select your monitoring outs (for example, “Digi 002 main outs”) as the output. By holding down the Control key, you add a second output (designated by the plus sign next to the output assignment).

Double that entire process by adding a second set of Instrument and audio tracks for each instrument (“Battery 2,” “Btry2Audio,” etc.). Make the second set inactive to preserve CPU cycles. Using that method, I had six total instances of instruments, with half of them inactive and ready to activate when needed. Save your session as a template so you can call up your mixer with all those settings intact every time you start a new session.

When you're happy with a performance on a particular Instrument track, record-enable its associated audio track and then press Record. Once it's recorded to disk, make the Instrument track inactive and move on to the other tracks. If you need to go back and make changes, reactivate the Instrument track, make changes and re-record it. Pro Tools playlists are also a big help here. For each record pass you do, track it to a new playlist, so you can go back in time and compare each record pass. You can also use playlists in that way to comp together different variations of a similar theme, which is helpful for changes over the course of a song.

The flexible and streamlined nature of Instrument tracks makes for intuitive creative work. The basics are covered here, but there's much more that you can accomplish by digging into the wealth of new MIDI features in Pro Tools 7.1. With Instrument tracks integrated into Pro Tools, they can only expand from there.

Digidesign's Music Production Toolkit is available for Pro Tools LE and M-Powered systems running 7.0 and higher at a cost of $495. The package is a combination of Pro Tools enhancements, including a boost to 48 stereo tracks, Beat Detective capabilities and the MP3 Export option, as well as these plug-ins:

Digidesign Hybrid — Part of Digidesign's recent Advanced Instrument Research group, Hybrid is a high-definition synth that combines analog waveforms with digital wavetable synthesis.

Trillium Lane Labs TL Space Native Edition — TL Space is the latest in a growing line of convolution reverbs designed to emulate actual spaces.

Digidesign Smack! LE — This compressor sports a stunning analog look and an aggressive sound.

SoundReplacer — This Audiosuite plug-in has been around for several years and offers file-based replacement of drum tracks or anything else you want to throw at it.

DINR LE Noise Reduction — Another longtime Pro Tools plug-in that is mostly used to reduce unwanted noise from audio.


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