McSweeney has had a rich career of Jazz and Broadway performances with some of the world's finest musicians since being chosen to perform at the Monterey Jazz Festival at age 16 with the All Star Big Band fronted by Thad Jones and Mel Lewis.
She has performed with Dizzy Gillespie, Lee Konitz, Joanne Brackeen, Dave Liebman, Lewis Nash, Holly Hoffman, Larry Goldings, Gil Goldstein, Rick Margitza, Mike Wofford, Frank Wess, Dennis Makrel, Renee Rosnes, Bucky Pizzarelli, Vic Juris, Mike Le Donne, Bucky Pizzerelli, Victor Lewis, Howard Alden, Ken Peplowski, Stacy Rowles, Diva and Maiden Voyage. She also has worked with famous conductors such as Leonard Bernstein, John Williams and Lalo Schifrin.
McSweeeny enjoyed a multi-year tenure in the pit orchestra for the Broadway musical Avenue Q and she has played at the Williamstown Theater Festival.