Kristin Miller originally shared this with us. We would like to share this afresh so that Jeff's students will have easy access to it. If this piece of music isn't worth the beautiful music and laughs alone, the video of these two boys is definitely worth watching just for their vowels, and the blond-headed boy's jaw drop. The vocal technique is a great model for young singers.
Here is the history behind it courtesy of Wikipedia:
The Duetto buffo di due gatti ("humorous 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"). Sometimes it is also performed by a soprano and a tenor, or a soprano and a bass.
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. Hubert Hunt putatively claims that the compiler was Robert Lucas de Pearsall, who for this purpose adopted the pseudonym "G. Berthold"