Gavotte is a French folk dance style. You can wear a tuxedo for
attending gavotte ceremony. Dress code is usually mentioned in
invitation.
View page
The Gavotte is a type of musical dance. There were many
composers during the Baroque period and beyond that wrote
gavottes.
View page
if it is a well-known classical gavotte like Gossec's "Gavotte
in D", it is in the Public Domain, and you can download it from one
of the PD sheet music sites free.