When Francisco Nuñez was growing up poor and lonely in Washington Heights – and his best friend was a second-hand piano – he wondered what it would be like to have lots of friends, from all different backgrounds.

Francisco Nunez has been tinkering on the piano since his mother brought home an out-of-tune clunker from the Salvation Army on West 46th Street when he was 5. These days, though, Mr. Nunez, 32, usually finds himself beside the piano, surrounded by 44 children ages 12 to 18 who run the gamut: rich and poor, parochial and public, white and black, Jewish and Muslim.