two people singing together is a duet
Quartet
they rub their knees together they use this as a mating call
they rub their knees together they use this as a mating call
Trio
a choir
People chosen to sing together are often referred to as a "choir" or "chorus." This group can vary in size and may perform a wide range of musical genres, from classical to contemporary. In some cases, smaller ensembles within a choir, such as quartets or vocal groups, may be formed for specific performances.
A chorus or choral! A choir.
It's a trio
Christmas carolers
The composer puts together musics for people to sing or play on instruments.
When four people sing together, it is often referred to as a quartet. In musical terms, a quartet typically involves four vocalists or instrumentalists performing together, harmonizing their voices or playing complementary parts. This term can apply to various genres, including classical, jazz, and contemporary music.
Drama Club Glee Club