Definitions

1. noun

A symbol or sign used in ancient Greek music notation to indicate a pitch, or a musical interval.

“The ancient Greek music notation system used a diesis to indicate a specific musical interval.”

2. noun

A musical interval of seven semitones.

“The diesis is an important concept in music theory, particularly in the context of ancient Greek music.”

3. noun

A pitch or note a semitone lower than the tonic.

“In the key of C major, the diesis is the note B, which is a semitone lower than the tonic C.”