The first time around, at Bunker's in 2011, Fitz & the Tantrums were a blast of spirited, self-penned vintage soul. Next time around, at the Basilica Block Party in 2012, Fitz & company were a pretty exciting party band.

On Sunday, at the sold-out Varsity Theater, Fitz & the Tantrums were somehow less exciting. Was it the muddy sound (it was difficult to decipher the lyrics)? The slickness of frontman Michael Fitzgerald? The inferior material on the L.A. group's just-released second album?

On their 2010 debut, "Pickin' Up the Pieces," Fitz & the Tantrums were like a soulful, modern-day Hall & Oates. Last month's release, "More Than Just a Dream," is dripping in 1980s pop influences, from new-wave to synth-pop.

Sunday's 80-minute show – the first of two sold-out nights at the Varsity this week – was as disappointing as the new album. Performing in dim light, Fitz didn't seem particularly into his songs. He came across like a faux soul man who would rather be part of a vintage synth pop ensemble like, say, Human League.

Tantrums sidekick Noelle Scaggs is a more soulful singer and graceful dancer (Ftiz is energetic but not a fancy dancer compared to her) but she seem relegated to being a hype-woman with occasional backup vocals. Watching this play out felt like watching Hall & Oates wherein John Oates was the dominant singer.

Nonetheless, Fitz & the Tantrums still managed to charm their burgeoning fan base, most of whom (by show of hands) had not seen them before. The group knows how to make synth-pop for club kids who like to dance. There were many winnings moments: "6 AM" with its intensity and tension, the snakey soul of "Dear Mr. President, the inspiring "L.O.V." and the spare, infectious radio hit "MoneyGrabber."

Here is Sunday's set list:

Keepin Our Eyes Out/ Don't Gotta Work It Out/ Winds of Change/ ??/ Breaking the Chains of Love/ ???/ Sweet Dreams (Eurythmics) / Out of My League/ ???/ 6 AM/ Dear Mr. President/ Tighter/ L.O.V. ENCORE MoneyGrabber/ The Walker/ Pickin Up the Pieces