In 1992, frustrated that major houses were reluctant to stage his epic operas, University of Chicago composer John Eaton got small, forming what’s now called the Pocket Opera Company of Chicago. The shifting lineup of about a dozen freelance singers and musicians performs inexpensive, portable productions with simple costumes–sometimes just a frilly shirt over street clothes–and minimal sets that rely heavily on projected images and creative lighting. Eaton, who funded the company in part with a MacArthur “genius” grant he won in 1990 and has written seven works for it, is just a few months away from retirement now. Though he’s still never had a multimillion dollar blowout at the Lyric, I imagine the creative freedom he’s had with the Pocket Opera helps compensate. His latest opera, a half-hour one-act called Youth, will receive its premiere this weekend, alongside revivals of two earlier pieces: Peer Gynt, an adaptation of Ibsen’s picaresque play, and Golk, a TV-age satire with a libretto by U. of C. English professor Richard Stern. Youth, which takes its story from a parable by Estela Eaton, the composer’s daughter, concerns Adam and Eve and their longing for a childhood they never had; they’re tempted with money and sex, and their mother, Gaia, is a junkie. Despite Eaton’s populist approach to opera, he’s yet to attract much of the crowd that supports affordable music-theater groups like the New Tuners, and part of the trouble may be his compositional style: rather than follow the current fashion and collage together a grab bag of idioms, he sticks with his own insistent, colorful voice, which is intricate, largely atonal, and loaded with microtones and multiphonics. With Youth, however, Eaton has made a small concession to convention: in Peer Gynt, as in many of the company’s productions, there are no vocalists, but just about all the instrumentalists also speak, sing, dance, or pantomime; Youth, by contrast, adheres to opera’s traditional division of labor, with vocalists singing and playing characters and instrumentalists accompanying but not joining in the action. The vocalists are soprano Sharon Quattrin, mezzo Jean Marie Minton, tenor Mark James Meier, baritone Jeffrey McCollum, and jazz and blues singer Stacia Spencer. Clarinetist William O. Smith plays Peer Gynt and flutist Mary Stolper doubles as the President in Golk; the rest of the instrumental sextet consists of violin, cello, piano, and percussion. Nicholas Rudall is the stage director, and Carmen Tellez conducts. Thursday and Friday, December 14 and 15, 8 PM, and Saturday, December 16, 2:30 and 8 PM, Duncan YMCA Chernin Center for the Arts, 1001 W. Roosevelt; 773-702-8577. The early performance on Saturday is of Peer Gynt only.