Traditionally a clarinet quintet is a chamber musical ensemble made up of one clarinet, plus the standard string quartet of two violins, one viola, and one cello. Now the term clarinet quintet can refer to five B♭ clarinets; four B♭ clarinets and a bass clarinet; three B♭ clarinets and two bass clarinets; one E♭ clarinet, two B♭ clarinets, and two bass clarinets; or one E♭ clarinet, two B♭ clarinets, one E♭ alto clarinet, and one bass clarinet. The term is also used to refer to a piece written for one of these ensembles.