Double flageolet in A, 8 keys. Bainbridge, London, 1821 31. Government Allocation to the University, 1991 (C.H. Brackenbury Memorial Collection). The flageolet is a type of duct flute (q.v.) i.e. an instrument of the flute family in which the sound is generated by directing the player’s breath through a fixed channel and against a rigid sharp edge or lip. In contrast, the modern orchestral flute is played by blowing across a mouth-hole.