One of the reasons William Parberry chose Handel's Messiah for the last concert he would conduct at the University of Pennsylvania was the extended "amen" at the end of the piece. On Friday evening at Irvine Auditorium, Parberry held his hands aloft for just one moment longer, soaking in that last note as the audience gave him a standing ovation.

"The Messiah has this beautiful finale, which I thought would be a good final punctuation mark to my career," he said. "It was a very emotional and stirring last note for me as well."

Parberry has directed Penn's University Choral Society, the University Choir, and the early music ensemble Ancient Voices in more than 270 concerts during his 45 years with the music department. He arrived in 1973 as a graduate student in musicology and accepted a faculty position after the role of choral director was vacated. Under his direction, the University Choir was chosen to perform with two popular artists — Michael Crawford, who had starred in The Phantom of the Opera, in 1998 and Barbra Streisand for her "farewell tour" in 2000.

Despite such career highlights, Parberry said that what he's going to miss the most about conducting is something much less glamorous — the rehearsals.

"This semester in particular, I've just cherished every moment of rehearsal we've had together," he said. "At the beginning of the semester, you have all these notes on the page and it's all just a jumble of nothing resembling music. But little by little, you see this improvement and the singers start to get excited about the music."

In his retirement Parberry plans to spend time traveling with his wife and visiting family members. But he hasn't ruled out returning occasionally for guest lectures or singing with other groups himself. According to Michael Ketner, the director of performance at Penn, the university will hire an interim choral director after Parberry's departure.

"Bill is a really smart musician, and one of the things that he brings is a real sense of knowing exactly what any piece is about," Ketner said. "He knows its complete history and why it was composed, and passes that knowledge on to the groups singing it."

Nancy Hornberger, a professor with Penn's educational linguistics division, has been singing with Parberry since 1986, a year after she became an assistant professor. In her first rehearsal with the Choral Society, she sang the Messiah. She performed one of the piece's alto solos during Friday's concert.

"I was hooked after that one rehearsal," she said. "Bill always has interesting things to say about the music and a huge amount of knowledge about the history of the music and the composer. It created a nice balance with the intellectual work I was doing."

Hornberger also said that Parberry's decision to open up the choral groups to the faculty and Penn community at large contributed to a better sound overall. More experienced singers were able to help younger singers develop over the years. Alumni returned to sing the Messiah on Friday, flying in from as far as Paris and Antwerp, Belgium. In recognition of Parberry's influence on his students, they decided to start a fund in his honor to provide financial support to future Penn music majors and choral scholars.

As Parberry turned around to take his last bow, he placed one hand over his heart and beamed at the audience, which included many former members of his ensembles.

"This was a profession that I enjoyed until the last minute," he said. "It's something that's a little hard to give up."