Duette buffo di due Gatti

The 'Duetto buffo di due gatti' (Comic duet for two cats) is a popular performance piece for two sopranos which is often performed as a concert encore. The 'lyrics' consist entirely of the repeated word 'miau' ('meow').
While the piece is typically attributed to Gioachino Rossini, it was not actually written by him, but is instead a compilation written in 1825 that draws principally on his 1816 opera, Otello. Sometimes the duet is also performed by a soprano and a tenor, or a soprano and a bass.