I spent some time this summer identifying the 42 jazz records used in the original version of John Cage’s Imaginary Landscape no. 5 in 1952. The original 78s were provided by dancer Jean Erdmann, who asked Cage to create the piece for her dance Portrait of a Lady. The piece was edited by Bebe and Louis Barron. Most of the 42 pieces can be identified through listening to a copy of Erdmann’s tape and referencing Cage’s score. Both sides of the 78 was used in almost all the samples I identified. 19 78s are listed below, 2 more are needed to complete the piece. Those listed in italics are a flip side that I couldn’t identify in the original. Most of the unidentified samples are under 2 seconds.

Here are the csound orchestra and score files and a sound file for the electronic part of Larry Polansky’s Horn.

horn-csound – csound orc and sco files

soundfile

sound file download link

James Tenney composed For Ann (rising) in 1969 and made several realizations with tape and signal generators. In 1991 I was asked to engineer a compilation of his early computer and electronic music, “Selected Works 1961-1969”. Instead of using one of the tape versions of For Ann (rising), we decided to realize it digitally in Csound. Jim described the piece to me over the phone. The piece consists of 240 sine wave sweeps, each of which lasts 33.6 seconds long and rises 8 octaves (4.2 seconds per octave). Each sweep has a trapezoidal amplitude envelope which rises from 0.0 to 1.0 gain in the first two octaves, stays at 1.0 for the 4 mid octaves, and drops from 1.0 to 0.0 for the top two octaves of each sweep. A new sweep starts every 2.8 seconds. The initial Csound orchestra and score was simply:

sr=44100
kr=44100
ksmps=1
instr 1
kf expon 40, 33.6, 10240
ka linseg 0, 8.4, 2000, 16.8, 2000, 8.4, 0
a1 oscil ka, kf, 1
out a1
endin
----
f1 0 16385 10 1
i1 0 42
i1 2.8 42
i1 5.6 42
and so on.....

The tuning difference between each successive sweep is a 12tet minor 6th.

For the final version on the CD, Jim asked me to extend each sweep by 4.2 seconds (1 more octave). We moved the start point to A0 (27.5 Hz) – the end of each sweep is A9 (14080 Hz). This increased the length of the piece slightly 240 * 2.8 + 33.6 + 4.2 = 11:49.8.

I have recently put together a new realization of For Ann (rising) in Pure Data. I am using metro, delay and vline to generate the sweeps in this version, as these objects (unlike many objects in PD) are sample accurate, and should give consistent tuning accuracy. Also for this realization, I have added the capability to perform the piece with the original 12tet minor 6th, a just 1.6 ratio, and a golden mean (phi) ratio between successive sweeps.

The PD patch is available here, for those who want to hear the piece.

Here are the slides from my presentation on designing the Erbe-Verb.

Reverb Toplogies and Design

Impulse Responses from various delay lines, in various states of repair –

Gibson GA-4RE (Telray Adineko echo). This circuit has considerable leakage of dry signal. You can hear that as the first impulse. The first “dark” impulse can be considered the impulse response of the delay. Also, there is no erase “head”. The brush simply writes over the charge on each rotation of the disk. The repeated echo isn’t due to feedback, but progressive erasure. Use the entire impulse response for an accurate emulation.

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Echoplex  (Original – pre “EP-1” Serial 709). A tiny bit of dry signal leakage. The tape impulse response shows up at about 360 ms. I am not sure why there is a sine sweep artifact in this IR (after the impulse). Possibly because the tape transport is so unstable, or perhaps interaction with the bias oscillator?

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Roland Space Echo RE-201. Much cleaner compared to the previous two devices. No way to turn the dry signal off (perhaps my Space Echo is in need of repair?).

UPDATED – New measurement from the PA input to get just the tape signal (no dry)

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DeltaLab Effectron. A very clever digital delay which measures differences between successive samples. An almost flat response which tilts slightly upward.

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Bright Analog Delay Pedal. A modern CCD (charge-coupled device) delay. There is a bit of ripple in the passband (could be a Chebyshev I filter?) which caused a noticeable resonance after multiple repeats.

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Dark Analog Delay Pedal. Another CCD delay. This one has a rounder, smoother filter response (possibly Bessel?), so no coloration after multiple repeats. Sharp rolloff at 2k for CCD aliasing rejection. You can see the signal leakage as a -60dB signal above 3k.

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The sine sweep and golay code methods of impulse response measurement used are from Edgar Behrdahl & Julius O Smith’s Transfer Function Measurement Toolbox

A PD echo patch with convolution in the feedback

download this: emuplex