The star was missing. He was sick. Constantine Maroulis didn't perform in Rock of Ages opening night in Houston Tuesday.

A representative from TUTS didn't know when Maroulis would return or the extent of his condition. The former American Idol star is apparently in Houston though. Just not on the Hobby Center stage.

But as far as the performance was concerned, it still rocked, and rocked hard. There was a bitchin' and roaring standing ovation, sparkling fake lighters swaying in the air and singing along to familiar tunes.

Maroulis was built to play Drew in Rock of Ages, a coming of age (sort of) love story where boy abandons his hard-rock dreams for a boy band and a girl strips to survive. Thanks to bodacious jams, they reconnect, rekindle their love and live happily ever after amidst big hair, gay colorful outfits and booze.

There were concerns by theatergoers of the show's efficacy without Maroulis. He has the voice, the hair, the bad-ass, yet positive attitude to play a likable character, and the fame to bring in the crowds (Maroulis did a number of pre-Houston-run interviews to promote the show, including one with CultureMap).

His understudy — New Yorker J. Michael Zygo — did not disappoint. Actually, his shy, wholesome approach fit the role of Drew flawlessly. And he can scream those high notes. No regrets here.

The show is jammin', encouraging head banging action, without Maroulis. (There will no be refunds given to ticket holders who bought expecting to see the famous hair).

Rock of Ages received plenty of Tony nominations including Best Musical, Best Performance by a Leading Actor, Best Direction, Best Costume and Best Sound Design, but did not win any. It was also nominated for two Drama League Awards and two Outer Critics Circle Awards. Meaning? People have noticed.

Using tunes from Journey, Styx, Bon Jovi, REO Speedwagon, Foreigner, Pat Benatar, Whitesnake and Twisted Sister, it is difficult to call this performance a musical, as it feels more like a concert with a storyline than anything else. Don't be surprised if the actors address you directly, especially if you are seated in the VIP Mosh Pit.

We know, a bit of an oxymoron, but the tables sponsored by Silver Eagle feature beverage and food service, where guests can sample eight artisan beers and themed snacks.

One of the most interesting parts of show are the allusions to the rich history of the Sunset Strip in West Hollywood. This mile-and-a-half stretch along Sunset Boulevard holds a rich music and cultural history, from its beginning of casinos and nightclubs in the 1920s to its stint as a playpen of the rich and famous in the '30s, to it's time as a hippie and punk rock hangout in the '70s, alcohol and drugs included. The '80s was all about glam metal, which is when Rock of Ages takes place.

Today, the Sunset Strip is also known for its wild display of colorful and risque billboards.

So aside from the familiar tunes, themes of nostalgia, historical preservation and the friction of personal goals and convictions against immediate needs — and perhaps a touch of transformation — add depth to the work. It may appear that Rock of Ages is just glitz, glam, a fog machine and loud (very loud) music. It isn't.

The work flows nicely, partly due to the flexible scenic design by Beowulf Boritt. Scene changes are smooth as the set mainly stays put. A screen embedded within the set projects music videos, pictures and footage designed by Zachary Borovay that relates to the emotional content and story development. Plenty of fog and an inventive lighting display by Jason Lyons morphed Rock of Ages from a great musical into a holistic experience.

The outfits? Outrageous. I didn't remember the '80s being that cool. Though I was more of a '70s boy, I think I may be growing up to the following decade. Yeap. Holding on to that feeling.

Rock of Ages presented by Theater Under the Stars at the Hobby Center for the Performing Arts runs through June 12. Tickets start at $24. For more information, click here.