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Monday, 25 August 2003

Going loopy ::

My ears are sore from being in headphones for most of the last 4 hours, so I’ll respond to my friend Jeff’s request that I let him know how I fared after he gave me some advice on making audio loops.

I’m late to the game of making rhythmic loops; it was such a painstaking process when I was last doing a lot of computer-based composing (1997-98), given the tools I had. I’d be happy if I could get one loop synchronized with a sequencer, and then just compose on top of that. Or I’d abandon the concept of a steady clock and just make ambient music. But now I’d like to experiment in more rhythmic veins.

I dove into Reaktor 4 earlier this week, and spent a lot of time just exploring the factory and user libraries. I eventually captured a long rhythmic improvisation using Le Truc (by Laurent Veliscek), an FM/resonator synth that puts a different timbre on each key. Ah, back to the DX7 days.

Then I had seven and a half minutes of playing, half of which I wanted to throw away, and half of which I wanted to cut up into phrases for further mangling and composition. First I tried Logic’s sample editor, but wasn’t convinced that its lack of a destructive crossfade editor (well, not one that I know of) was going to be a problem. Then I spent some time in Peak, which is a fine editing app, but I found myself daunted at the prospect of finding all the edit points and creating who-knows-how-many slices of such a long file without a proper bar/beat timeline.

That’s when I called Jeff, who pointed me back to Logic. The key in this situation was that the audio file is at a precise and constant tempo, and most of my rhythmic mistakes didn’t land on heavy downbeats. So the process was more time-consuming than difficult, something like:

• Import audio.
• Set the tempo (it was 100 bpm in Reaktor and it turned out to be exactly 100 bpm in Logic too; the advantages of software-generated audio!)
• Trim the audio object so that the downbeats line up with Logic’s timeline.
• Cut it up into (mostly) 4-bar objects.
• Edit the objects so that they made smooth loops. Surprisingly often, considering that I was playing live using odd sounds with some reverb on them, somewhere around half the chunks didn’t need any tweaking.
• Since I want to play with the loops in Reaktor (which probably means another iteration of the above steps in Logic, later), export each object to a separate audio file.
• Use Logic’s Time and Pitch Machine to destructively edit each file so that its length was precise, to compensate for the small inaccuracies introduced in making the loops smooth.

Cool. I went out on that polyrhythmic limb at the end of the original recording, so editing out the few good bits there was its own little adventure, fun enough to distract me from the previous mission of creating a collection of separate files for further mangling in Reaktor. OK, that’s a nice 35/8 loop... wow, it’s cool to play 16, then 17, then 18, then 19 eighths starting here...

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2003 > August

Building gnu readline 4.3 on Mac OS X >>

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