Here's an interesting tidbit contributed by inSync reader, Wade T, in response to our recent WFTD, Envelope Generator.

The term "envelope" in regards to sound comes from early electronic music, which was created by taking tapes of musical instruments or other sounds and running them through high pass, low pass, and band pass filters. The resulting tape "samples" (surprise, surprise) were snipped and kept in envelopes - the paper kind. Since part of the manipulation was the ADSR (attack, sustain, decay, release) of each tape sample, the sounds and the manipulation of the sound began to be called, in the parlance of the day, the envelope: "Which bassoon envelope are you using in that piece?" and so on.

With the introduction of synthesizers (which, like computers, took up vast amounts of space) the manipulation of sound was basically the same... synthesized waveforms run through filters, which affected timbre and the ADSR. It was only natural that the term "envelope" would migrate to new technology, and the circuits used to manipulate sound would be called an "envelope generator."