wah-wah

With an electric guitar, the wah-wah pedal controls the relative bass and treble response of a sound. Fully down it has a high treble tone; fully up it emphasizes the bass. The characteristic “wah-wah” sound is achieved by rocking the pedal back and forth.

whole-tone scale

A six-note augmented scale formed entirely of intervals of a whole tone, such as C-D-E-F-G -A.