Amy Whitcomb went to introduce the Vocalosity band Sunday afternoon at Centennial Hall.

Problem was there was no band, even though our ears told our brains that what we were hearing was a bass guitar thumping beneath the pulsating drum beats when bass Bryant Vance and tenor Cheeyang Ng teamed up on Bruno Mars's "Uptown Funk." And wasn't Nicole Weiss playing a saxophone during the Motown medley?

Amazing what beautiful music the human voice can create.

In every song they sang, the 10-member Vocalosity a cappella troupe, playing a UAPresents family series show, sounded like they were backed by a rock band complete with scorching heavy-metal-kissed lead guitar (RJ Woessner) and drum kit with clashing top-hat cymbals (Tracy Robertson).

Most of that was coming from vocal percussionist Robertson, a beatboxer extraordinaire who at one point tried to have the audience of 1,600 play along. Moment of honesty: We sounded pretty terrible. Robertson, who wears his long dreads piled high on his head like a heavy turban, has a beautiful gift that is harder to pull off than it looks.

Vocalosity's show took us to the heart and soul of a cappella, which has gained in popularity in the past few years since the release of the a cappella-centered comedy "Pitch Perfect." Vocalisity is the product of "Pitch Perfect" music director and arranger Deke Sharon, an a cappella champion who has taken that concept from the big screen to the big stage. The troupe surveyed the history of a cappella from Beatles hits done in the several early a cappella styles from Gregorian chants — "Strawberry Fields" sounds refreshingly new and vibrant thrown back to the ninth century  — to sea shantyand barbershop quartet, then turned to the present with Bruno Mars' "Uptown Funk" and beyond. A medley of Motown hits from the 1960s through 2000s, including a flash of rap courtesy bass James Jones, was strung together to tell one continuous love story. Toss in some true confessions by cast members, show tunes including a mashup of  "West Side Story" and "Sound of Music" that was pretty hilarious and contemporary pop hits from Justin Bieber's "What Do You Mean" to Ariana Grande's "Dangerous Woman" sung in pretty impressive five-part harmony by the Vocalosity ladies Whitcomb, Weiss, Nattalyee Randall, Hannah Juliano and Kelli Koloszar, and you had 90 minutes of non-stop infectious entertainment. 

One of the afternoon's highlights was soprano Whitcomb's pretty incredible cover of Led Zeppelin's "Wanna Give You My Love," backed up by Woessner channeling Jimmy Page's lead guitar complete with that metallic screech. Robertson pounded out the thundering percussion while Vance delivered a driving thump on bass guitar and Jones created a solid rhythm guitar. It was one of the most compelling, surreal and spot-on Zeppelin covers we can remember and one that probably inspired a few of the dozens of kids in the audience Sunday to think about joining an a cappella group. 

Contact reporter Cathalena E. Burch at cburch@tucson.com or 573-4642. On Twitter @Starburch

I cover music for the Arizona Daily Star.