The Duetto buffo di due gatti or "humorous duet for two cats" is a popular performance piece for two sopranos which is often performed as a concert special encore. The lyrics consist entirely of the repeated word "miau" ("meow") to sound like cats are singing. It is also performed by a soprano and a tenor, or a soprano and a bass.
While the piece is often attributed to Gioachino Rossini, it was not actually written by him, but is instead a compilation written in 1825 that draws mostly on his 1816 opera, Otello. Hubert Hunt putatively claims that the person who put it togeter was Robert Lucas de Pearsall, who for this purpose used the pseudonym "G. Berthold".
Les Petits chanteurs a la croix de bois, Concert in Seoul, Korea, Nov 30, 1996