In front of a sold-out crowd Friday night at the Fox Theatre, R&B singer Monica made her triumphant return to the concert circuit while headliner Trey Songz delivered a less than par performance.

It would be fair to say that plenty of eyes were on Monica as she made her first major concert appearance in nearly five years.

Her signature vibrato and complex runs were welcomed from the second she took the stage. A familiar face joined her onstage. “Sunday Best” and “American Idol” semi-finalist Jermaine Sellers was among her all male background performers.

Though the performance of Sellers and the rest of the trio seemed unorganized and lacked focus, fans primarily kept their attention on the main attraction of the moment.

She started with the classics early in her 45 minute set that included three wardrobe changes that ranged from hip-hop to formalwear.

Monica was barely a teen when she started in the industry, making her grand entrance into the music scene with her debut CD “Miss Thang” in 1995. As she sang songs from that project like “Before You Walk Out of My Life,” and “Don’t Take it Personal,” she thanked her fans for 16 years of support – including her sixth CD “Still Standing.”

She paid special homage to her musical idol Whitney Houston through a snippet of “You Give Good Love” and a full fledged performance of “I Have Nothing.”

While it was easy to embrace the pleasurable mix of nostalgia and now Monica offered through her set, the segment of the evening Trey Songz offered to his fans was much less fortunate.

Songz is a one-trick pony, and his show was little more than an extended sex act, with average singing and mediocre energy.

His third return to St. Louis in less than two years, Songz latest visit was to promote his upcoming CD Passion, Pain and Pleasure (which hits stores September 14). But the show was a painful overload of passion with little pleasure for the non-diehard fans who were hoping to see the artist who was able to move through the ranks of the R&B scene – thanks in part to personal woes of Chris Brown and Usher Raymond.