OK, I liked Styx. Not that I ever actually bought one of their records--I was, after all, well over 13 by 1975, when the group broke into the Top 40. But unlike most of my friends, I didn't reflexively retch the moment "Lady" or "Come Sail Away" came blaring over the radio. I enjoyed the group's blend of kitschy pomposity and self-parody, admired its sense of harmony and musical structure, and appreciated the broadly theatrical sensibility of Dennis DeYoung, one of the band's two principal songwriters and a technically superb tenor. Two of the band's most popular albums, Paradise Theater and Kilroy Was Here, were concept records, and the latter was even staged in 3,000-seat halls. So it's no surprise that since Styx's displacement from the teen-idol pantheon DeYoung has moved into musical theater--recording an album of show tunes by writers ranging from the Gershwins to Andrew Lloyd Webber, playing Pontius Pilate opposite Ted Neeley's Jesus in a touring revival of Jesus Christ Superstar, and penning a pop-opera adaptation of The Hunchback of Notre Dame. Though that project may never make it to Broadway (it seems to have been permanently preempted by the Disney cartoon version of the same story), it's got a strong score that holds up well against shows like Les Miserables, Miss Saigon, and The Phantom of the Opera (and far surpasses dreck like Elton John and Tim Rice's Aida). Hunchback tunes like "With Every Heartbeat" and "Esmerelda" are certainly as good as the Les Miz hits "Bring Him Home" and "On My Own"--though DeYoung's influences are Italian gondolier ballads rather than French chansons; after all, this is a keyboardist who honed his skills on the accordion at age seven. DeYoung's admirers will have a chance to hear selections from the Hunchback and 10 on Broadway albums as well as Styx's repertoire when the Chicago-based singer takes the Rosemont Theatre stage this weekend. He'll be accompanied by a rock band and 50-piece orchestra conducted by Arnie Roth; he'll also be joined by Nashville singer Mike Eldred, who played Quasimodo in a regional production of Hunchback, and winsome belter Dawn Marie, DeYoung's sister-in-law and his leading lady on the Hunchback CD. The former teenyboppers who probably constitute DeYoung's core audience must be making good money: the concert reportedly is almost sold-out even though tickets cost between $35 and $75 (in addition to $10 to $15 for parking)--the same prices commanded by the modern musical-theater extravaganzas that DeYoung's chart toppers of 20 years ago helped inspire. Saturday, 8 PM, Rosemont Theatre, 5400 N. River Rd., Rosemont; 847-671-5100 or 312-559-1212.