Joshua David Birnbaum

On Sept. 11, 1999, according to a trippy-looking flier that Sam and Marcel Birnbaum have saved, there was a rave in Johnson City, Tenn., and DJ Samsson was on the bill. "This New York City DJ's trance set will set you off like a highly reactive chemical," the flier promised.

Two years later, DJ Samsson, also known as Josh Birnbaum, 24 and straight out of Columbia University, had set aside his turntables for yield tables, at least for the day, and was at his job at Cantor Fitzgerald as an assistant bond trader.

But for Mr. Birnbaum, working on Wall Street was mostly a means to an end: saving up enough money to open his own recording studio. He already had a small studio set up in his apartment near Columbia. "His dream was music, always," said Marcel Birnbaum, his mother.

Mr. Birnbaum's father, Sam Birnbaum, is no fan of techno or trance or any of the other myriad forms of dance music always pounding from Josh's speakers. But he did not mind that Josh chose a D.J. name that reflected the love and respect he had for his father. "Are you kidding?" Marcel Birnbaum said. "He was honored."