Gonville & Caius Musical Society (GCMS for short) exists to promote music in Gonville & Caius College (one of the colleges of the University of Cambridge). It was founded in the late nineteenth century, amidst the growing musical climate in Caius that was fostered by the appointment, in the 1880s, of Charles Wood as 'organist scholar' and later fellow. These days, it is run by a committee of two fellows of the college and around 20 junior members, most of whom are elected at the Society's AGM in the summer (which all students at Caius are welcome to attend).

The Society runs an orchestra and chorus for the members of the college, both of which perform, under the direction of student conductors, at the College Concerts  that happen in the Michaelmas and Lent terms. In the summer it puts on some kind of show, usually a musical. In addition, members of the college and of the general public are all welcome to come to the recitals  that take place every Saturday and Sunday in the Auditorium  on I staircase, Caius Court. A less formal outlet for performance exists in the Scales Club, which was founded in the 1860s and later absorbed into the Musical Society; this takes place once a term, and is a fun evening of musical and dramatic performances.