An angel represented singing or playing a musical instrument, common in Marian, celestial, and liturgical imagery.
A musical angel sings or plays an instrument as part of heavenly praise. Such figures appear around the Virgin, Christ, altars, vaults, choir screens, and scenes of Assumption or Coronation.
Etymology
Musical from Greek mousike through Latin and French; angel from Greek angelos.
Sculptor Notes
The instrument cannot be treated as an accessory. Hand placement, finger action, breath, shoulder position, and the weight of the instrument should be believable. Instrument families also create different silhouettes: harp, lute, gittern, viol, organ, trumpet, and pipe all ask for different compositions.
References
https://www.metmuseum.org/art/collection/search/464358