American violinist William de Pasquale has died at the age of 78. He played at the front of the Philadelphia Orchestra violin section for four decades in various concertmaster positions.

Born in Philadelphia, de Pasquale studied at the Curtis Institute of Music with Veda Reynolds. In 1958 he made his first appearance with the Philadelphia Orchestra as a student audition winner, and in the same year he travelled to Salzburg on a Fulbright Scholarship to study and play in concerts. Returning to the US, he became concertmaster of the New Orleans Philharmonic. In 1963 he joined the Philadelphia Orchestra as a regular member, and was made an associate concertmaster three seasons later.

When Normal Carol retired as the Philadelphia Orchestra concertmaster in 1994, de Pasquale became acting concertmaster for a year. He was appointed second concertmaster in 1995, and then co-concertmaster in 1999. He retired from the orchestra in 2005.

William de Pasquale's three brothers all played with him in the Philadelphia Orchestra: Robert was a second violinist, Joseph the principal viola, and Francis a cellist. The brothers played together in the De Pasquale Quartet. De Pasquale's widow Gloria is a cellist in the Philadelphia Orchestra.

William de Pasquale taught violin at the Esther Boyer College of Music at Temple University in Philadelphia, and was principal string coach and artistic adviser for the Philadelphia Youth Orchestra.