Starting Sunday, guests at San Francisco’s Parc 55 Hotel might wonder why the halls are alive with the sound of music.

The American Conference of Cantors and the Guild of Temple Musicians will hold their annual joint convention there this year. That means impromptu songfests and jam sessions could spring up.

“People sing everything from opera to country,” says Kay Greenwald, cantor emerita at Congregation Beth Am in Los Altos Hills and president of the ACC. “There’s spoofing of classical and some serious classical music.”

The convention also means getting down to serious business for about 200 of America’s cantors.

“Our most important continuing education vehicle is the convention,” Greenwald adds. “There’s a tremendous amount of learning that goes on.”

This is the first time the convention is being held in San Francisco (Monterey hosted it in 1992). It runs from Sunday, June 29 through Thursday, July 3, and features workshops, lectures and guest speakers. It also includes a pair of public concerts and opportunities for out-of-towners to experience the full monty, San Francisco style.

We’re talking a night on the town with Beach Blanket Babylon.

Alan Lew (rabbi emeritus at Congregation Beth Sholom in San Francisco) will deliver the keynote address and lead breakout sessions on Jewish meditation. Also scheduled is psychologist Trish Davis-Wick, who leads workshops on management and organization.

To keep things on key, Jewish music superstar Rick Recht will help cantors brush up on their song leading.

Odd as it may seem, not every cantor has the whole “guitar-sing-along-clap-your-hands” thing down.

“We wanted to improve our skills, so we invited Rick,” says Roslyn Barak, cantor at S.F.’s Congregation Emanu-El and the convention co-chair. “He’s a marvelous song leader and entertainer, and we’re really pleased he’s with us.”

That takes care of the casual sing-along. As for classical grandeur, the convention will sponsor two public concerts.

The first is a performance of Elizabeth Swados’ “Bible Women” on Monday, June 30 at S.F.’s Congregation Sherith Israel.

The other has an intriguing local angle. Swiss-born composer Ernest Bloch (1880-1959) spent many years living in the Bay Area. In 1929, Congregation Emanu-El in San Francisco commissioned a new choral work, Bloch’s “Avodat HaKodesh (Sacred Service).”

It had its American premiere in 1938 at the S.F. synagogue. Seventy years later, it returns to Emanu-El for a performance Tuesday, July 1. The Ludwig Altman Music Fund of Congregation Emanu-El is co-sponsoring the concert.

“We have seven magnificent baritone cantors,” Barak says, “with full orchestra and 100 chorus members from all over the Bay Area.”

As with any convention, the social aspects rank highly. For the more than 200 cantors, organists, cantorial soloists and song leaders attending, the event offers a chance to catch up.

“A lot of our colleagues come from states in the middle of the country where there might be only one or two cantors in the whole state,” Greenwald says. “So [the convention] is looked forward to by people.”

Adds Barak, “We’re a fun group.”

And, obviously, a talented group, skilled as musicians, pastoral counselors, b’nai mitzvah trainers and Jewish community leaders.

Still, conventioneering cantors have to work hard to keep the ol’ basso as profundo as possible.

“We always continue to hone our skills,” Greenwald says. “You just want make them sharper. I continue to take voice lessons and will until there’s nothing left to work with.”

Two concerts for the public

The American Conference of Cantors/Guild of Temple Musicians’ 2008 convention will present two concerts open to the public.

“Bible Women,” a song cycle by Elizabeth Swados, along with a tribute to Israel, is 8 p.m. Monday, June 30, at Congregation Sherith Israel, 2266 California St., S.F. Tickets: $18.

A 70th anniversary performance of “Avodat HaKodesh (Sacred Service)” by Ernest Bloch is 8 p.m. Tuesday, July 1, at Congregation Emanu-El, 2 Lake St., S.F. Tickets: $18. Information on both performances: (800) 838-3006 or online at www.accantors.org.