His 30th Anniversary Is Something to Sing About : Celebration: Chapman Music Dean William Hall will present an ambitious Beethoven choral program at the Performing Arts Center.

When William Hall accepted a one-year contract to teach at Chapman College 30 years ago, he would not have considered bringing the Pasadena-based William Hall Chorale with him to Orange County.

The county was, after all, considered a cultural backwater.

“Every now and then, somebody from another planet, planet Zoid of Music, would come into the Santa Ana High School Auditorium and that would be as if they had crossed the Red Sea,” Hall remembered. “They came down the 5 freeway and they performed out in this vast wasteland. . . . And now so many wonderful things have happened.”

Today, Hall--now dean of the 2-year-old School of Music at Chapman University--will celebrate his 30th anniversary at the school by leading choirs formed from the Master Chorale of Orange County and Chapman singers.

The William Hall Chorale is no more, having merged with the Master Chorale in 1989, when Hall accepted the directorship of the less-established group. And several fine local venues long ago replaced the high-school auditorium. Today’s ambitious program, Beethoven’s Mass in C and his Ninth Symphony, will take place at the Orange County Performing Arts Center.

For the Mass in the 3,000-seat Segerstrom Hall, the 140-member Master Chorale will join with the 70-member Chapman University Choir, which Hall also trains. For the Ninth Symphony, the chorus will number 245 as an 80-voice alumni choir, assembled just for this event, and the 25-member Chapman University Singers replace the school choir.

The alumni choir is being rehearsed by two Chapman graduate students--Alvin Brightbill, a faculty member at Saddleback Community College, and Thomas Sheets, who teaches at Long Beach City College.

Rounding out the evening will be the Master Chorale Orchestra, assembled from 67 free-lance musicians.

Hall is looking forward to the results. Despite the massive numbers, he is confident the performers will be able to cover the music’s full range, from “a hushed pianissimo to a bravura type of double forte.”

Soloists for both works are Chapman University graduates. Soprano Susan Taylor Mills, mezzo soprano Adrien Raynier, tenor John Nuzzo and bass Roger Lindbeck will be featured in the Mass; Kay De Vries, Debbie Cree Smith, Steve Dunham and Louis Lebherz will, respectively, take the soprano, mezzo, tenor and bass roles in the Symphony.

“Chapman has had a strong background in vocalism for a long time, and we have over a hundred now that are in opera houses all over the world. It’s really wonderful to bring back eight of our former students who are successful in their vocal careers.”

* Master Chorale, Chapman singers and alumni choir. Tonight at 8, Orange County Performing Arts Center, 600 Town Center Drive, Costa Mesa. $15 to $40. (714) 556-6262.