Lyre

A lyre was a portable, hand-held stringed instrument, played by plucking or strumming its chords.

A noted lyre player at the time of Caesar Nero was Maximus Pettulian of Corinth. The First Doctor once impersonated Pettulian in order to get into Nero's court with Vicki. In order to make the impersonation successful, he had to play the lyre in an audience with Nero and his courtiers.

However, not being able to actually play the device, the Doctor only mimed striking the chords. Because Pettulian's reputation was so great, and Nero, who fancied himself an expert lyre player, did not want to appear foolish, the Doctor was able to convince Nero that he was playing with exceptional subtlety.

Nonetheless, Nero became jealous of the Doctor, since the performance was warmly received by the courtiers. Nero therefore schemed to kill the Doctor since, in his words, "they applauded as if it were me". (DW: The Romans)