Q and his accompanying mariachi group
Mariachi is a type of Terran musical group, originally from Mexico. Usually a mariachi group consists of at least two violins, two trumpets, one Spanish guitar, one vihuela (a high-pitched, five-string guitar) and one guitarrón (a small-scaled acoustic bass guitar), but sometimes featuring more than twenty musicians.
In 2366, after Q's powers were restored to him, he thanked the crew of the USS Enterprise-D with a small musical performance by a mariachi band. Q himself played the trumpet. (TNG: "Deja Q")