He was exposed to Broadway at the age of fourteen when he was inspired by the Richard Rodgers musical No Strings.
While attending Hofstra University he won the role of The Boy in off-Broadway's The Fantasticks and dropped out of school as a sophomore.
[1] After a short stint in the production, Carnelia pursued songwriting and, later, musical theatre composition.
He composed lyrics and music for Three Postcards, with a book by Craig Lucas, which was staged off-Broadway by Playwrights Horizons in 1987 and revived by Circle Rep in 1994.
For the musical Sweet Smell of Success (2002), he teamed with composer Marvin Hamlisch,[6] with whom he also composed songs for the 2002 Nora Ephron play Imaginary Friends.