Crest of the Wave - musical - was created in 1937.
Old Crest on a New Wave was created in 1980.
The crest.
crest
The distance from crest to crest in a transverse wave is called a wavelength.
Wave Length
It's not an idiom. It means just what it says -- something is on the crest of a wave. The crest is the top of the wave.
In a wave, it is called the wave length.
Crest.
The crest of a wave is its highest point, as opposed to the trough of a wave, which is its lowest point.
constructive interference
The high point of a wave is its creast or peak.
Wavelength