Friday, February 22, 2008

Statescapes and the theory of long-period delays

A compositional technique that I've become fond of are my Statescapes. These are improvisational compositions formed using a sound-on-sound technique: a sound is played into a delay line set up for a very long delay time, and (usually) a large amount of feedback so that there are many repeats. Doing so quickly builds up a sound collage that makes for a fascinating and useful background for playing additional parts against. These counterpoints in turn become part of the collage, are played off of by further counterpoints, and so on.

Some time ago, I developed a "spectral chart" of delay time values and the effects produced:

The human ear reacts in qualitatively different ways to these delay ranges. The flanging and doubling ranges are so short that the ear cannot detect the repeats; these short delays cause phase cancellations (the comb filter effect) which are perceived as spectral alterations. Modulating the delay time within the range produces the classic effects: the "jet plane" noise for flanging, and the high-presence, moving sounds associated with chorusing. The doubling range is the shortest range in which the ear can tell that repeats of the sound are happening. The effect is so named because it sounds similar to the old recording trick of "double tracking", that is, recording two as-identical-as-possible performances of the same part, and then mixing them together.

The reverberation range is the range of delays typically associated with rooms large enough for natural reverberation to be noticeable. Repeats in this time range will create the effect of being in a large space. (Said large space will, however, sound pretty unnatural; there is a lot more going on in real reverberation than simple delays, and modern electronic reverb effects are much more sophisticated than simple delays.) The echo range is where the ear really begins to separate the individual repeats. This is the classic yelling-into-the-canyon effect: the original sound and the returned echo are readily discernible.

When the delay time exceeds roughly 2 seconds, a funny thing happens. The ear no longer associates the repeats with the original sound, even though they may be identical except for level. Instead, the repeat is perceived as a new sound, separate from the sound that created it. This is the effect that Statescapes are based on.

I first heard the technique in 1980, on Robert Fripp's "Exposure" and "God Save the Queen / Under Heavy Manners" albums. Fripp credits Brian Eno with introducing him to the long-period delay technique. Eno, in turn, claims that the technique was in use as early as the 1950s; if so, the identity of its inventor is probably lost to history. Fripp and Eno originally implemented the delay line using a pair of Revox reel-to-reel tape recorders. The two machines were set up next to each other, with the take-up reel removed from the first machine and the supply reel removed from the second machine. The tape was threaded from the supply reel of the first machine, through its heads, across to the second machine, through its heads, and on to its take-up reel. The first machine recorded and the second one played back; a mixer combined the playback with the original source for re-recording. The delay time was adjusted by moving the two tape machines closer together or further apart.

Fripp originally called his execution of the technique "Frippertronics". The Revox implementation worked well enough for Fripp to produce four albums with it -- two with Eno, one with a band, and one solo, plus some backing tracks on his "Exposure", Peter Grabriel II, and Daryl Hall's "Sacred Songs" albums. However, re-recording tape tracks in this manner has some problems. Tape always produces a certain amount of noise, and the re-recording results in noise buildup. Also, each re-recording causes some loss of high frequencies. Combined, these phenomonea produce a rather lo-fi effect, which is noticeable on the early Fripp efforts. (It didn't help that at the time, Fripp was using a guitar pedalboard containing some not-so-distinguished stomp boxes.) So when technology first made it feasible to achieve long delays in a purely electronic fashion in the early '80s, Fripp upgraded, first to an Electro-Harmonix delay, and then to the digital TC Electronic 2290. This had several advantages. Besides eliminating the mechanical complexity, it also made it possible to modulate the delay time while running, and to combine two or more delay lines into multi-tap or parallel effects. It didn't suffer from the noise building and high-frequency loss of the tape setup. And, most basically, it was capable of longer delays. The tape setup was limited to delays of about four seconds -- the length of tape between the two machines sagged and tangled when longer delays were attempted. The 2290, in contrast, was capable of 8 seconds out of the box, and more with memory expansions. The 2290s facilitated a further advancement in composition; delays could not be made so long that they were difficult to discern even by a knowledgable listener cued to listen for them, and the delay time need not be a constant for every repeat with the use of two or more devices. Fripp first introduced this new configuration on the King Crimson "Three of a Perfect Pair" album, and then on his solo "1999" album. At this time, he changed the name he used from Frippertronics to Soundscapes.

For years, I wanted to attempt the technique myself, and especially after my first listen through "1999". I was absolutely blown away by that album, by the very long loops which added much more depth to the pieces and made them less predictable, and by the greatly improved fidelity with the TC 2290s vs. the Revox setup. But from my own perspective, the 2290 had one big problem: it was expensive. I had to wait another eight years, but Boss finally fixed the problem in 2005 by releasing the DD-20 GigaDelay:

This inexpensive unit is capable of a whopping 23 seconds of delay! In addition, it has a number of different modes for delay time modulation (most of which I haven't actually explored yet). Plus, despite being packaged a a stomp box, it's actually a high-quality device that is capable of easily accepting line-level inputs. The day I received mine, I routed the Juno-106 through it and just started playing. After a few trial runs, "West Virginia" was the result. Twenty-five years after I first heard of Frippertronics, I finally had access to the technology. And right away I knew this was something I could do. I see why Fripp got hooked on it; it's absolutely addictive, and the results often surprise even the performer. One big differece in my own technique is that Fripp is a guitarist (he now uses a Roland guitar synth), while I'm a keyboard player. There's a different feel when playing keyboard parts into the setup vs. guitar parts.

Since "West Virginia", I've done some experiments on expanding the concept: combining the delay with a self-looping patch ("North Dakota" and "South Dakota"), adding a ping-pong effect to break up the delays and spread the stereo image ("Connecticut"), and the most out-there bit, creating a very complex set of interlocked delay lines with Csound ("Maryland"). Why state names? In Fripp's earlier efforts, he used years as arbitrary song titles for many of his Frippertronics/Soundscapes pieces. I wanted to go with that basic concept but not just copy what Fripp did. Being an American, I hit on the concept of using the names of U.S. states. How do I pick the particular ones? Randomly, for the most part. North and South Dakota are so named because they were both produced with the same basic setup. Other than that, there is no correlation between any particular Statescape and the actual state. It's just a name. (The exception is going to be Alabama, which because it's my home state, will get something special.)

I've got lots of other ideas for things I want to do with this. And there's still 45 states and the District of Columbia to go!


bughouse said...

very cool. i have done this quite a bit in the past, and recently have been wanting to go back to long loop overdub compositions, but i couldn't really *explain* why. never thought about it in the way you have.

heh - now i'm on craigslist looking for DD-20's. hmmmm, wonder why 23 seconds?

LDT said...

I started doing this for the exact same reasons as you in 1998 when I got my hands on a DOD D12 which featured 12 seconds of delay. I picked up a DD-20 a couple years ago and love it.

I'm curious why you call it "statescapes" instead of "soundscapes".

Examples of what I've done can be heard at my myspace - - as well as