b. 27 April 1962, Santa Cruz, California, USA. McSweeney trained as a classical musician, studying piano at the age of five, then violin at eight. In her teens she played concert performances on piano but while at junior high school began playing electric bass. It was in high school that she first played the acoustic bass and, by now was interested in a career as a jazz musician and so she chose this instrument as her primary means of expression. At the age of 16, she appeared at the Monterey Jazz Festival in a big band directed by Thad Jones and Mel Lewis. In Los Angeles she studied at California State Northridge under Dave Young who introduced her to Ray Brown with whom she also studied, later becoming a pupil of John Clayton. In addition to Brown and Clayton, McSweeney has also cited Richie Beirach as one of her mentors.
Throughout most of the 80s, McSweeney worked in Los Angeles jazz clubs, at festivals and studio sessions. In 1993, together with her husband, valve trombonist Mike Fahn, she moved to New York where she found work on record dates, at clubs and in pit bands for many Broadway shows. She has appeared at jazz festivals in the USA and Europe. Among numerous and diverse artists with whom she has played are Lynne Arriale, Dizzy Gillespie, Donny McCaslin, Rick Margitza, Sherrie Maricle’s big band, DIVA, and Jimmy Witherspoon, as well as with classical groups under Leonard Bernstein, Lalo Schifrin and John Williams. Technically accomplished and highly inventive, McSweeney’s playing is complemented by her considerable gifts as a composer and arranger. In the early 00s, McSweeney led her own groups for concert, club and recording dates, also appearing regularly as sideman with several leaders including her husband.