Phasing as Musical Technique

Keen for discussion and to learn of other examples of use of phasing as a musical technique. I don’t mean phasing like a Mutron BiPhase phaser etc, I’ll sight the examples I know & love:

Steve Reich – It’s Gonna Rain (1965)

“It’s Gonna Rain is a minimalist musical composition for magnetic tape written by Steve Reich in 1965. It lasts about 17 minutes and 50 seconds. It was Reich’s first major work and a landmark in minimalism and process music.

“It’s Gonna Rain … is a very heavy piece written in the shadow of the Cuban Missile Crisis, and the voice is a spectacularly moving, intense voice about the end of the world.” (Steve Reich)

The source material of It’s Gonna Rain consists entirely of a tape recording made in 1964 at San Francisco’s Union Square. In the recording, a Pentecostal preacher, Brother Walter, rails about the end of the world, while accompanying background noises, including the sound of a pigeon taking flight, are heard. The piece opens with the story of Noah, and the phrase “It’s Gonna Rain” is repeated and eventually looped throughout the first half of the piece.

For the recording, Reich used two normal Wollensak tape recorders with the same recording, originally attempting to align the phrase with itself at the halfway point (180 degrees). However, due to the imprecise technology in 1965, the two recordings fell out of sync, with one tape gradually falling ahead or behind the other due to minute differences in the machines, the length of the spliced tape loops, and playback speed. Reich decided to exploit what is known as phase shifting, where all possible recursive harmonies are explored before the two loops eventually get back in sync. The following year, Reich created another composition, Come Out, in which the phrase “come out to show them” is looped to create the same effect.”

Steve Reich – Come Out

So I knew of these works for many years, and while its easy to ‘unsync’ two buffers nowadays, its the ideas & intent that intrigue me… and the potential.

I have always been utterly fascinated by a work by composer Arvo Part, because I could not understand how it was made. This work:

ARVO PÄRT – Sarah Was Ninety Years Old

I was reading a book, Arvo Part in Conversation, and was motivated to start this thread as he explained the techniques used, which includes phasing:

I’d love to learn of other works, past or present…

Steve Reich’s Pendulum Music (1968) would be another:

Note: I posted same to Lines forum here & have lots of great input

UPDATE:

Got distracted while editing some video and tried some experiments:
First phasing 2 loops with a one frame difference:
Left = 2 second 48 frame loop
Right = 47 frame loop
Takes about 90seconds to loop around, so if you count it after each loop it is 1 frame out of sync, then 2, 3, 4, 5 etc…

Clean audio panned as per vids
(MKH8040x2+8050 plus MKH8020x2 inside box on floor)

Clean audio with tuned resonator on each side, panned as per vids

PT calculates its 119.88bpm vs 122.43bpm (at 23.976fps)

then tried four loops: golf club hit loop 48 frames vs 47 vs 46 vs 45 – pitched each & panned…

My brain keeps trying to assign something to the one/start of a bar… but its interesting when a pattern inverts eg that 4 loop version starts with 4 pitches descending high>low, but at some point my brain assigns the one to the lowest note & a pattern emerges with the pitches all going up eg at 1.07

Just an experiment but kind of interesting to hear it…