William Edward Trusten, 51; HIV Lecturer, Musician

William Edward “Bill� Trusten, 51, veteran pianist and assistant conductor of the highly regarded Gay Men’s Chorus of Los Angeles, died June 9 in Los Angeles of cancer.

Born in St. Paul, Minn., Trusten studied piano at USC and became an administrator with the USC Department of Biological Sciences. He became known for annual lectures on the progress of HIV research and his experience living with HIV.

Trusten joined the Gay Men’s Chorus as a singer at its start in 1979. Two years later he became its accompanist and held the position for 18 years. He served on its board of directors and in 2001 created his post of assistant conductor, resigning only recently because of declining health.

He made two international tours with the chorus, to Europe and to the former Soviet Union. His piano accompaniment, earning praise from Times and other reviewers, is featured on the PBS documentary of the European tour, “Out Loud.� Trusten also arranged music, wrote lyrics and scripted the chorus’ recent concert, “Red, White & Blues.�