John Eaton is generally considered one of the most original composers writing opera today. Now he's taken another bold step--setting up a small music-theater outfit that counters the pretensions and snob appeal of grand opera. With his traveling band of troubadors, the Pocket Opera Company, this University of Chicago prof hopes to reach out to new, younger audiences. For the company's debut Eaton has composed an intimately scaled opera that will serve as a prototype for the group's future presentations. Let's Get This Show on the Road is a humorous, lighthearted look at the complicated act of creation, a theme that has preoccupied Eaton throughout his four-decade career; its six episodes, adapted from the book of Genesis by poet Eugene Walter, cover the creation and fall of mankind, the story of Noah's Ark, and other weighty topics. On the other half of this double bill, the New York New Music Ensemble will present the first-ever staging of Eaton's one-act opera Peer Gynt (the music was premiered here a year and a half ago). In Eaton's version, based on the Ibsen dramatization of a Norwegian fable, the instrumentalists and the actors are one in the same; this move not only reduces the necessary personnel but also efficiently incorporates music making into the drama. Joining the New York ensemble in Let's Get This Show on the Road are a quartet of fine young singers: Lauren Miller (soprano), Julia Bentley (mezzo-soprano), Harold Broch (tenor), and Jeffrey Morrisey (baritone). Michael Phillips is staging both operas; Cliff Colnot conducts. Wednesday and Thursday, 7:30 PM, next Friday, December 10, 8 PM, and next Saturday, December 11, 2 PM, Court Theatre, University of Chicago, 5535 S. Ellis; 702-3427.