Ring around a single reed, at the base of the tongue; Through moving it, one changes the relative length of the tongue, thus influencing the sound and pitch of the reed; NB¹: ➺ Bridle (double reed); NB²: ➺ Absolute / Relative length.

Nowadays [i.e. late 20th century; ws] usually a firm elastic band; The wire or hemp wound around the base of single reeds used in eastern Europe, &c. serves also as a bridle.