Inches Per Second

Inches Per Second. Sounds a little dirty, doesn't it?

But it wasn't that long ago that this was a common measurement, specifically of how fast the tape was zipping past the head in a tape-recorder. The standard was 7 1/2 ips, but for professional quality that would be doubled to 15 ips. If you were just recording voices in a meeting you might save tape by dropping down to 3 3/4 ips or even 1 7/8 ips if you didn't really care whether it was clear.

Musically, though, it was Les Paul who figured out that you could slow the tape down to half-speed, record a track at the slower speed, then speed it up again to get a speedy musical effect that would be virtually unplayable at the speed you were hearing it. He used the effect on many recordings, and I remember reading an interview with Chet Atkins (with whom he used the technique) in which he described meeting some young guitar student who had been diligently practicing one of these speeded-up lead lines, and Chet was shocked that the kid had mastered it at the double-speed pace.

It's been used since then as well; the example that everyone knows is the 'harpsichord' solo in the middle of John Lennon's "In My Life," which is actually a double-speed piano solo. I always assumed everyone knew this, but apparently it's not obvious unless you (as I did when I was a kid) have played around with changing speeds on your tape recorder.

The effect on the human voice is known as the 'chipmunk' effect, after its extensive use by Ross Bagdasarian's Alvin and the Chipmunks. If you search YouTube you can find The Chipmunk Song slowed down to where the chipmunk voices sound normal. Well, normal-ish. In order for the chipmunks to be comprehensible when speeded up, the singers have to overpronounce all the lyrics, and they sound a little otherworldly. (although not as otherworldly as Dave, who in the slowed-down version is identified as Satan)

The best example I can find of altering speeds, however, is something that was pointed out to me by a colleague, who played me a version of Dolly Parton's "Jolene" slowed down. It's nothing Dolly ever did on purpose, but it highlights the mastery of her voice and her musicians when you realize that this is like 'listening under the microscope,' where any imperfection would be magnified. Check it out: