Fantastic anaecdote about a music professor/Formula One car (thanks, QrazyQat) racer whose perfect pitch let him detect cheaters by listening to their engines:
I also used to tell my competitors what gear ratios they were
running by comparing their cars' pitch with mine when we were
adjacent on the track, identifying the musical interval
between the two pitches (minor 2nd, Major 3rd, etc.), and then
using temperament ratios to figure out the difference in RPM.
It got a little busy out there sometimes with all the
braking, cornering, multiplication and division.I had the usual suspects memorized. Piece of cake – a major
second is 9/8, major 3rd is 5/4, P4 = 4/3, P5 = 3/2 etc.
For minor intervals I'd just interpolate from the nearest
major/perfect.
(Thanks, Jeremy!)