Duet

"A duet is a musical composition for two performers in which the performers have equal importance to the piece, often a composition involving two singers or two pianists. It differs from a harmony, as the performers take turns performing a solo section rather than performing simultaneously. A piece performed by two pianists performing together on the same piano is a "piano duet" or "piano four hands". A piece for two pianists performing together on separate pianos is a "piano duo".

"Duet" is also used as a verb for the act of performing a musical duet, or colloquially as a noun to refer to the performers of a duet." - (en.wikipedia.org 05.10.2020)