One famous aria after another: the operatic hit parade began as the bus pulled away from the depot, empty. La donna mobile" from Verdi's "Rigoletto" was followed, somewhere on the West Side Highway, by "Nessun dorma" from Puccini's "Turandot." The A's and that high B at the end were thrilling. And then the bus turned onto Clarkson Street, on the way to the first stop on the M8 line. "This is difficult sitting down," said the driver, Christopher G. Dolan, 51. "You got to be standing up." Mr. Dolan ... has been a New York City driver for 27 years, starting in the Bronx and then transferring to Manhattan. You never know whom you will meet on a bus - he married one of his passengers. "That's worth my $2," said Elaine Smalls, who boarded at Eighth Street and Avenue C. He started as a baritone. On the job one day in 2002 - he was on the M10 then - he picked up a passenger on Eighth Avenue whom he recognized as Vincent La Selva, the artistic director of the New York Grand Opera. "I called him over, which surprised him, being recognized on the bus, and I said, 'What does somebody have to do to get an audition with you?' He handed me his card and said, 'Give me a call.' " Mr. Dolan did, and soon he was in Mr. La Selva's studio, plowing through aria after aria. He remembers what Mr. La Selva told him when he finished: "I love your voice, but you're not a baritone. Go home and learn to be a tenor and come back." Mr. Dolan did as he was told: he worked on getting his voice up to a higher tessitura.