What do you do next?

If you are William Bolcom - and only he fits the description above - you head for Moab, Utah, to see "Lucrezia" staged at Star Hall, perform some chamber music and offer a free concert at Old City Park.

It's an extraordinary set of circumstances, but fans of the Moab Music Festival, which opens this week, have learned to expect the unexpected.

At the festival, classical chamber-music concerts share billing with jazz, musical theater, Latin American music and new compositions, often performed by their composers. And in keeping with the festival's theme of "music in concert with the landscape," performances happen in unusual venues.

This year, pianist Christopher Taylor will play Olivier Messiaen's monumental piano work "Vingt regards sur l'enfant-Jésus" in a natural stone grotto reached by jet-boating down the Colorado River. Latin-jazz specialist Paquito D'Rivera will play tango music in a tent beside the Colorado near scenic Castle Valley. And Bach's unaccompanied violin and cello suites will be heard alongside a hiking trail winding through a redrock landscape.

"Every concert is unique," said Michael Barrett, artistic director of the festival. "There's no filler here. Every concert is specifically about something, and created for the space it's in."

In a festival that's known to be adventuresome, the inclusion of a couple of "pocket" operas - "Lucrezia" is paired with John Musto's new opera "Bastianello" - is just another new adventure.

The two short operas were commissioned to celebrate the 20th anniversary of the New York Festival of Song, a music series also headed by Barrett, along with colleague Stephen Blier. Musto and Bolcom developed their operas from librettos by Mark Campbell, who adapted classic Italian storylines into comedies with a modern twist.

"It's kind of an extraordinary thing to have a librettist write for two composers at the same time," Barrett said. "But Mark came up with ideas for each composer that they took on heartily."

For Bolcom, Campbell turned a somber play by Machiavelli into a lively sex farce. Bolcom, in turn, composed the piece as a Spanish operetta - a zarzuela - filling its score with tangos and fandangos, and its scenes with sly comedy. "A zarzuela as imagined by the Marx Brothers," The New York Times quotes Bolcom as saying.

In a Tribune interview, Bolcom said he has been fascinated with Latin American music since the 1960s and has been studying and collecting it ever since. "Lucrezia" allowed him to incorporate a music style he loves in service of Campbell's hilarious poetry. "Mark's an extremely witty writer who loves arcane rhymes," Bolcom said. "It's very refreshing."

Barrett said Bolcom was the right genius for the job of setting "Lucrezia." "I don't know if he is our most important living American composer, but he's my favorite living composer," Barrett said. "He has the most 'chops' of any composer. He can write just about anything, can write it quickly and can write in any style. And when it is done, it will sound like his music."

Barrett is further impressed by Bolcom's versatility, which will be on display in Moab. "He's also been a performer throughout his career," Barrett said. "He knows what it is to be on the stage, play music and give something to an audience."

Bolcom will perform in a Sept. 6 chamber music concert and participate in two free events: a rehearsal and discussion of his works, and a city park concert of American song, for which he will be piano accompanist for his wife, mezzo-soprano Joan Morris. He'll also be in the Star Hall audience for "Lucrezia" when it is performed Sept. 5 on a double bill with Musto's opera, "Bastianello."

For "Bastianello," Campbell adapted an Italian folk tale about a man whose disgust for the stupidity of his new bride leads him to swear that he won't return to her until he finds six people more stupid. It's a conceit that gives Musto ample excuse for writing a returning Calypso melody that accompanies various feats of silliness - such as a man trying to put on his trousers by jumping into them from a chair.

The opera takes a tender turn when the man realizes his lack of wisdom in leaving his true love over an insignificant argument; the sixth fool he discovers is himself. "I'm pleased that [both operas] are so much fun," Barrett said. "Everyone thinks they have to write the great American tragedy - but people want to go to the theater to enjoy themselves. Sure, they want to come away with a moral question that's been posed, or to fall in love with a character, or to have a personal catharsis and come out the other side. These operas do all of that, and they are musically challenging - but they are funny and fun. It's the ultimate combination."

Concerts galore at The Moab Music fest

Transportation is provided to events outside Moab. Season tickets can be purchased for $125 (excludes benefit events). Tickets for all events of an individual weekend (excluding benefit events) are as follows. Weekend I: $40; Weekend II: $30; Weekend III: $55. For tickets and venue information, call 435-259-7003 or visit www.moabmusicfest.org.

Weekend I

Aug. 28 » Colorado River Benefit Concert, featuring a jet-boat trip to a natural stone grotto where pianist Christopher Taylor will perform Messiaen's "Vingt regards sur l'enfant-Jésus"; noon; $300.

Aug. 29 » Festival Opener concert, featuring chamber music of Handel and Bohuslav Martinu; Tent at Red Cliffs Lodge; 6 p.m.; $25, $5 for students.

Aug. 30 » Paquito D'Rivera Ensemble playing tango music; Tent at Red Cliffs Lodge; 6 p.m.; $25, $5 for students.

Sept. 1 » Labor Day Family Picnic Concert; popular music of the early 20th century featuring jazz artist Paquito D'Rivera, composer/pianist William Bolcom and mezzo-soprano Joan Morris; Old City Park; 2 p.m.; free.

Weekend II

Sept. 4 » Colorado Benefit Concert II, featuring clarinetist Derek Bermel playing his own "Thracian Sketches for Solo Clarinet," and chamber music of Brahms and César Franck; noon; $300.

Sept. 5 » Free rehearsal discussion. Composers William Bolcom and Derek Bermel rehearse and discuss their works with MMF artistic director Michael Barrett. Star Hall; 11 a.m.; free.

Sept. 5 » "A Night at the Opera," featuring Western premieres of a pair of "pocket" operas - William Bolcom's "Lucrezia" and John Musto's "Bastianello." Both operas are sung by soprano Lisa Vroman, tenor Paul Appleby, baritone Patrick Mason and bass Matthew Boehler, all New York Festival of Song artists; Star Hall; 7 p.m.; $15; $5 for students.

Sept. 6 » "A Celebration of American Chamber Music" featuring festival artists performing works of Scott Joplin, Darius Milhaud, William Bolcom and Derek Bermel; Festival Tent at Onion Creek; 6 p.m.; $25; $5 for students.

Sept. 7 » House Benefit Concert. Music of Brahms and Mendelssohn at private home in Castle Valley; $200.

Weekend III

Sept. 9 » Ranch Benefit Concert. French Celtic Music at a scenic ranch north of Moab; 5 p.m.; $100.

Sept. 10 » Piano (and Violin) Talk features Beethoven sonatas with pianist Paul Hersh and violinist Axel Strauss; Star Hall; 7 p.m.; $15, $5 for students.

Sept. 11 » Colorado Benefit Concert III, featuring music of Beethoven and Ravel; noon; $300.

Sept. 12 » "A Musical Walk" takes hikers down a trail to a secret location to hear unaccompanied violin and cello sonatas of Bach performed by violinist Jesse Mills and cellist Tanya Tomkins; 10 a.m.; location TBA; $50 - sold out.

Sept. 12 » "Crypto-Judaica" features Paul Woodiel on fiddle and Christopher Layer on pipes and flute, along with other world music performers playing folk music from the Sephardic Jewish tradition; Sorrel River Ranch; 6 p.m.; $25, $5 for students.

Sept. 13 » Chamber music of Mozart, Dvorák and Mendelssohn; Sorrel River Ranch; 6 p.m.; $25, $5 for students.