Refining Your Audio Grooves

By Joe Gore

In our last few installments, we've looked at ways to generate new song-starter ideas from simple materials, using basic Pro Tools editing commands and simple AudioSuite plug-ins. We made a generic drum loop a little less so via pitch shifting, time compression, and reversing, and then melded three distinct bass ideas into a single interlocking pattern spanning several stereo tracks.

This time around, we're going to look at some of the ways you can make your ideas groove — by using some of the very same techniques. These moves will come in handy any time you're trying to make two or more rhythmic layers work with, not against, each other.

In this month's practice session (which you can download here PC | Mac), we're returning to the drum loop and bass riff we previously concocted. (For this months download, I've bounced all the bass stuff to a single stereo file.)

So, let's take audio inventory. How does it sound? My take: Some interesting sounds, though the drum track feels a little lightweight relative to the bass, and the overall groove seems a bit lazy and low-energy.

Nudge, Nudge
Much has been written about the delays introduced by digital processing, especially when you incorporate plug-ins. You could probably figure out the exact numeric values of these delays, but all my fave Pro Tools gurus go strictly by feel. Sometimes the best remedy for an underachieving groove is the simplest one: sliding the tracks around in tiny increments until they feel right.

Now it's your turn. Let's see whether we can improve the groove by nudging the bass track relative to the drums. Both the drum and bass parts are eight bars long, and both start precisely at the beginning of bar three — you can verify this via the Start, End, and Length fields at the top of the screen. For example, when you select the bass figure, the numbers read 3|1|000, 11|1|000, and 8|0|000, respectively.

Let's set the nudge to a small value. Click on the nudge field in the black bar above the ruler, select the minutes/seconds option, and specify ten milliseconds. A millisecond may seem like an impossibly tiny increment, but you'll soon see that adjustments of just a few milliseconds can vastly alter a groove. In fact, the ten-millisecond resolution is rather coarse, but I find it makes a good starting point for roughing out a feel before fine-tuning with the one-millisecond setting.

The nudge key commands are easy to remember: Command (Mac) or Control (PC) + < for pushing a part earlier in time, and Command/Control + > for later. Or you can use the minus and plus signs on your computer keyboard's numeric keypad to move files earlier or later in time. You may not be able to see the part move if you're set to a wide-screen view, but you can verify the new location via the Start, End, and Length fields, like so:

The bass part has a lazy feel to begin with, and it's exaggerated by the reversed sounds on some of the downbeats. Nudge it earlier in time by a click or two. Better, huh? Decide which location feels best, and then refine the positioning by switching to the one-millisecond setting. (Cool trick: Command/Control + m and Command/Control + / nudge your selection back and forward by the next-finest nudge resolution, without resetting the nudge field. Note how the m and / keys frame the < and > keys. Comfy! You can also toggle through nudge resolutions by typing Command + Option + plus/minus sign (Mac) or Control + Alt + plus/minus sign (PC). Operate by feel, not thought. Nodding, tapping, or wriggling may help. (FYI, my favorite start point for the bass loop was 2|4|945.)

Groove Steroids
Now, how can we add a little backbone to the drum part? By adding more crap, of course!

I found a loop that reinforces the basic beats of the pattern, but with more aggressive kick and snare sounds. Audition "TooShortLoop" in the region list by clicking on it while holding down the Option (Mac) or Alt (PC) key. (Note how the cursor changes to a speaker icon.)

Make a home for the new part: Create a new track (Command/Control + shift + n) and specify "stereo audio track," preferably using the key commands (Command/Control + left/right arrow selects mono or stereo tracks, and Command/Control + up/down arrow toggles between Audio, Aux, Master, and MIDI track types). In grid mode, drag the loop into the session, snapping it to the beginning of bar 3, like so:

How does it sound?

Putrid!

For starters, it's way out of time. Select the new part and look at the length field at the top of the screen. Oops. It's less than four bars — too short.

Solo and loop the new part to confirm that it loops cleanly. (Hint: It does.) So we just need to stretch it to the proper length. You can do so with the AudioSuite Time Compression/Expansion plug — if you're a loser. Instead, using PT 6's super-cool TC/E Trimmer tool. Select it by clicking on the trimmer tool till the TC/E icon appears (it's got a little clock on it), or better yet, use the F6 key. Verify that you're in grid mode, with the grid set to the maximum resolution of one measure. Now drag the left edge of the new loop toward the downbeat of bar 7, release, and voilá! Pro Tools resizes the loop for you. Verify the new length with a quick glance at the length field. It should now read an even 4|0|000.

In general, incorporating additional loops like this is one good way to expand a cool pattern into a cool arrangement. Once you have several layers that work well together, you can deploy them structurally — adding the percussion filigree on the choruses, say, or introducing the walloping backbeat during the solo section. It's arrangement by successive addition and subtraction.

So how does our beat sound now? Definitely less putrid.

Beat Surgery
But can we make it sound good? Let's try some microsurgery. Slice the new loop into beat-sized segments like we've done the last few months: Engage Tab-to-Transients and Command Focus mode (for a refresher on these modes, see the March 2003 column), then slice by pressing the tab and B keys in alternation. (Beware: Sometimes the tab-to-transient function gets a little too enthusiastic and perceives false transient points within a single hit, especially after loud, compressed accents like the ones here. Be sure to eyeball the slice points as you proceed. If you get a false transient, just hit tab again till you land on the right beat.)

Once the file is sliced, try quantizing all the segments to grid. Since this pattern has some sixteenth notes, set the grid resolution accordingly. (Try using the Command + Option (Mac) or Control + Alt (PC) + plus/minus sign commands to toggle through the various grid resolutions.) If that sounds good, select all the new segments and press Command/Control + f to smooth them out with a batch crossfade. (The default crossfade setting of 10ms is usually a good bet for moves like this.)

I think we can still improve the groove with some more anal — er, precise — adjustments, so undo the batch crossfade and zoom in close on the individual segments. With the nudge resolution set to one millisecond, try lining up the slices, beat by beat. Sometimes, especially on notes with a lot of bass content, you want to align the waveforms so they're as in-phase as possible — that is, so that most of the individual waves are pointing in the same direction, like so:

Do the same with each of the ensuing hits. You can advance from one slice to the next with the tab key (turn tab-to-transients off), or back up to the previous slice with Option/Alt + tab. A fast way to focus on a single segment is to select it and zoom in by pressing the e key in Command Focus mode. Scrutinize the graphics, but let your ears make the final calls.

After lining up all the hits, the results sounded a little too thick for me, so I muted the second kick accent of each measure, like so:

Once you have something you like, you may want to consolidate it as a single file that's easier to incorporate throughout your arrangement. Do so with the Option/Alt + shift + 3 key command. Don't simply select the first and last slices, which you may have moved. Instead, make sure the selection reaches from exactly 3|1|000 to 7|1|000, like this:

But now the loud, reverberant snare at the end of the pattern gets overbearing when it arrives every two bars. Let's transform it into a longer phrase. First, slice the pattern in half and slide the second half up to bar 9:

Then select the first part of the beat and duplicate it twice to fill in the empty space (Command/Control + d).

Sounds better, huh?

Bongo Fury
Try all of the above again on your own with the "TooLongLoop," a funky bongo track.

Create a new stereo track. Place the file. Listen. Oops! It's — surprise — too long! Resize it with the TC/E trimmer. Slice with Tab-to-Transients. Align the slices. Make it sound good. Consolidate the new file.

Chances are, you find this process time-consuming and tedious. But after you work with it for a while, you'll….oh, who am I kidding? It will always be time-consuming and tedious! Granted, Pro Tools TDM systems let you automate this process via the Beat Detective window, and you can even extract groove templates from audio files, which you can use to modify other MIDI and audio tracks. But now matter how spiffy the Pro Tools system or how experienced the engineer, monster grooves inevitably require a fair amount of careful detail work.

Subtractive Arrangement
When you finally have all the tracks grooving to your satisfaction, try creating a little arrangement. One possible procedure is to paste all the patterns out in a solid grid, and then start muting regions. This is a good way to experiment with different ways of building and breaking down your grooves. Here's one possible 16-bar section:

Finally, I made a little mp3 mix, which I've included with the download ("GrooveWorkshopMix.mp3"). We'll be looking at mix techniques in depth later this year, but here are some of the moves I used:

• I inserted an Extra Long Delay plug-in on the bongo track and adjusted the delay to tempo with these settings:

• I trashed up the new drum loop with Digi's Lo-Fi plug-in, removing some of the clattery top end by lowering the sample rate and adding a touch of saturation.

• I compressed most of the tracks, added some tube-simulating overdrive, and inserted a Sony Inflator — an ass-kicking limiter — on the master output channel.

I think it sounds pretty cool, but I also think you can do something cooler. Prove me right!

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