Push the envelope

[Bruce Dykes]

-----Original Message-----
From: Paul McFedries <lists at mcfedries.com>
To: ADS-L at LISTSERV.UGA.EDU <ADS-L at LISTSERV.UGA.EDU>
Date: Wednesday, July 26, 2000 5:41 AM
Subject: Re: Push the envelope


>After some canny hints from Barry Popik and Leslie Savan, I think I've
>tracked down the origin of "pushing (the edge of) the envelope." It seems
>that the envelope metaphor is derived from mathemetics, where an "envelope"
>is the outer boundary of a set of curves. In aeronautical engineering,
>flight characteristics such as air speed, rate of climb and descent, and
>rate of directional change can all be represented graphically as curves. So
>the outer boundary of those curves -- the envelope -- represents the
>theoretical limit of the aircraft's performance.


This also explains another, rarely heard usage, describing musical sounds,
especially in terms of attack (the beginning of the sound), sustain (the
middle), decay (the fade), and release (the close).

I first heard envelope used to refer to a soundform's characteristics in the
context of the neonatal days of the electronic synthesizer, but it likely
may have been in use before then. I don't think any but the geekiest of
geeky musicians (Laurie Anderson, Thomas Dolby, Brian Eno, et al) are much
concerned with soundforms anymore, so it's likely not used much anymore, but
I could be wrong...

bkd