The curious ninth-century Epistle to Dardanus by
Pseudo-Jerome
refers to an instrument called chorus, which is defined as follows: chorus quoque simplex pellis cum duabus cicutis aereis, et per primam inspiratur, per secundum vocem emittit (a simple skin with two bronze pipes, into the first of which one breathes, the second emits sound
). This definition fits two different instruments equally well: the bladder pipe and the early bagpipe, and indeed the (now destroyed) thirteenth-century...