It was probably not a flageolet, though that instrument suggests itself as particularly appropriate to the episode.

But the good Dr.
Burney says that the flageolet was invented by the Sieur Juvigny, who played it in the "Ballet Comique de la Royne," the first French pastoral opera, in 1581.

It could have been a recorder, the ancestor of the flageolet, which was probably in use in the fourteenth and surely in the fifteenth century.

But more probably it was one of the older reed instruments of the oboe family, the pommer or possibly a schalmei.

The schalmei is mentioned as far back as Sebastian Virdung's "Musica getuscht und ausgezogen" (1511).