quartets

noun

1. 1

   A music composition in four parts, each performed by a single voice or instrument.

   “A string quartet.”

2. 2

   The set of four musicians who perform a piece of music together in four parts.

   “A quartet of violinists.”

3. 3

   A group of four singers, usually males, who sings together in four-part harmony.

   “A gospel quartet.”

4. 4

   Any group of four, especially people.