“Set” (2000 words); “Interval Class” (400 words); “Pitch Class” (250 words)

Author: Roeder, John
Publication details: New Grove Dictionary of Music and Musicians, 2d ed. London: Macmillan Reference, Ltd.

Weblink: 

• Pitch Class: https://oxfordmusiconline.com

• Interval Class: https://oxfordmusiconline.com

• Set: https://oxfordmusiconline.com