E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Waits.
Street musicians, who serenade the principal inhabitants at Christmas-time, especially on Christmas Eve. From Rymers Fdera we learn it was the duty of musical watchmen to pipe the watch nightly in the kings court four times from Michaelmas to Shrove-Thursday, and three times in the summer; and they had also to make the bon gate at every door, to secure them against pyckeres and pillers. They form a distinct class from both the watch and the minstrels. Oboes were at one time called waits.
1
Dr. Busby says the word is a corruption of wayghtes, hautboys, transferred from the instruments to the performers.Dictionary of Music.