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Quartets and other ensembles

The cello is a member of the traditional string quartet as well as string quintets, sextet or trios and other mixed ensembles.There are also pieces written for two, three, four, or more cellos; this type of ensemble is also called a "cello choir" and its sound is familiar from the introduction to Rossini 's William Tell Overture as well as Zaccharia's prayer scene in Verdi 's Nabucco. Tchaikovsky 's 1812 Overture also starts with a cello ensemble, with four cellos playing the top lines and two violas playing the bass lines. As a self-sufficient ensemble, its most famous repertoire is Heitor Villa-Lobos ' first of his Bachianas Brasileiras for cello ensemble (the fifth is for soprano and 8 cellos). Other examples are Offenbach 's cello duets, quartet, and sextet, Pärt 's Fratres for eight cellos and Boulez ' Messagesquisse for seven cellos, or even Villa-Lobos' rarely played Fantasia Concertante (1958) for 32 cellos. The 12 cellists of the Berlin Philharmonic Orchestra (or "the Twelve" as they have since taken to being called) specialize in this repertoire and have commissioned many works, including arrangements of well-known popular songs.