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.
Mr. Nunez is the founder and director of the Children's Aid Society Chorus, which in two weeks will take part in its first competition, the Prague International Choir Festival and Competition. His charges will perform ''Ave Maria'' by Brahms and ''Nukapianguaq,'' a chant-based Inuit piece. This will be the group's first trek abroad.
The trip costs $1,700 a child, and Mr. Nunez said only one could pay the full amount. So he held benefit concerts to make up the $60,000 deficit. Still, he has panic attacks -- as he did last Monday, after he learned that a parent had not applied for a passport for her child.
Such headaches have been a part of Mr. Nunez's life since the society hired him in the late 1980's to be an after-school counselor and play basketball with the children. But Mr. Nunez, who has a degree from New York University, thought music would be more effective than hoops at keeping youths off the streets. In 1990, the society let him start its official chorus. Two feeder choruses have been added. Mr. Nunez holds auditions at the society and at schools in poor neighborhoods. For every 100 candidates, he said, he might select 10.
The first three years were painful, he recalls. He had no parental support, and ''the kids sounded like foghorns.'' But he worked out a curriculum that includes intonation, enunciation and sight-reading. And his lessons don't end when the music stops. If a parent forgets to pick up a singer after practice, he drives the child home. He asks to see chorus members' report cards and calls tutors for those not faring well. When one child threw a cat into a washing machine, ''I got a whole team of social workers for him.''
His technique seems to work. ''I couldn't sing before,'' said Paul McElfresh, 12, one of the few boys in the choir. ''Now I sing in my sleep.''
Today, parents talk of the trust they have for Mr. Nunez as he guides their children. And he trusts his performers in the competition. ''I expect to come out in good standing, not seventh out of five,'' he said. ''We can make this happen as any homogenous group.'' KAREN HSU