Composer John Eaton has always wanted his pocket operas to reach an audience broader than the crowd at a typical opera house--his hour-long productions, which require minimal sets and only a small ensemble of instrumentalists and vocalists, are designed to be portable. But though they've impressed a number of critics and academics, Eaton's works have yet to achieve popular success: his classical or literary adaptations (Peer Gynt, Antigone, Travelling With Gulliver) tend to be too cerebral for musical-theater fans, and his rich and distinctive idiom, which encompasses microtones and other unconventional sounds, isn't melodic enough for Puccini lovers. (I attended a Lyric Opera press conference a few years back that was intended to tout the company's commitment to living American composers, and when I brought up Eaton's name, the silence was deafening.) Eaton retired from the University of Chicago two years ago and now lives in New Jersey (he's renamed his Pocket Opera Company of Chicago the Pocket Opera Players), but he's returning to town for the local premiere of his latest,...inasmuch, and a revival of Don Quixote. Both works on this double bill are typical of the genre Eaton has almost single-handedly established: the instrumentalists double as characters, and expressive vocal passages and clever wordplay abound. In Quixote, there are no vocalists; the musicians "sing" with their instruments and deliver spoken dialogue (they also use their instruments as props--a clarinet might be brandished as a sword, for instance). In contrast,...inasmuch revels in the voice, employing seven singers. Its libretto, by Estela Eaton (the composer's daughter), is a fable about linguists on a tropical isle who plot to kidnap a trio of parrots from a princess who cannot speak; the birds provide her voice, singing in a lost Aztec language. The six-piece instrumental ensemble includes clarinetist Eric Mandat, cellist Craig Trompeter, and percussionist Tim Clark, and among the lead vocalists are tenor Mark James Meier and sopranos Sharon Quattrin and Tony Arnold; Carmen Tellez conducts and Nicholas Rudall directs. Saturday and next Saturday, September 14 and 21, 8 PM, and next Sunday, September 22, 2 PM, Duncan YMCA Chernin Center for the Arts, 1001 W. Roosevelt; 312-738-5999.