Reality TV takes its stars only so far. Home Free, winners of the 2013 "Sing-Off" a cappella series on NBC, know that. That's why the Minnesota-based quintet has worked so hard since then.

Home Free's improvement was evident in abundance Sunday night in its debut at the Minnesota Zoo. The soldout show was more focused, crisper, funnier, cuter, more inventive, more sophisticated and more country-centric without being off-putting to non-Nashville fans. In short, it was a delight – cheerily entertaining and musically satisfying.

Like all successful country bands, Home Free delivers the 3 H's – harmonies, hair and humor. The four-part harmony is impressive (the fifth dude is a rhythm machine), the hair (and beards) is flowing and the humor is integral to setting Home Free apart.

With three Nashville-produced albums on Columbia Records since "Sing Off," 15-year-old Home Free is concentrating on country music. Not only do they interpret such big hits as Florida Georgia Line's "Cruise" and Little Big Town's "Boondocks" but they have a couple of choice originals, including the clever talk-sing "Champagne Taste" ("on a beer budget"), which is fun, funny and so true.

The group is adroit enough to update its repertoire to include Maren Morris' "My Church," which is heating up country radio this spring, and a gospelly treatment of Shakira's "Try Everything" (from "Zoolandia") which featured brand-new member Adam Chance, who joined last month.

Chance, who sang with the Street Corner Symphony (runners-up in Season 2 on "Sing Off"), was not assertive enough on his lead vocal opportunities but held his own on the harmonies.

Throughout the program, lead vocal chores traded off, with Austin Brown and Rob Lundquist taking the most turns. But the spotlight shone brightest on bassist/chief spokesman/main songwriter/head jokester Tim Foust, who used his deep voice and quick wit to fire off cheeky and sometimes corny bits.

Foust talked about Home Free's concert in Topeka, Kansas, being picketed by the Westboro Baptist Church. He joked: "I'm happy we're doing well enough we can be hated."

While Foust may have dominated the spotlight, it was co-founder Adam Rupp, the group's beat-boxer, who stole the show. In a nearly 9-minute solo stint under dramatic lights, the beat-box marvel did an acoustic drum workout (seated on a stool, miming like he was drumming) and then one on electronic drums. In fact, he was like a one-man EDM band with just his voice..

That wasn't the only highlight. Here were others:

  • The breezy, energetic, so-called "Butts" medley, complete with nonstop choreography, compiled songs from various styles of music that deal with derrieres, including Trace Adkins' "Honky Tonk Badonkadonk," Sir Mix-a-Lot's "Baby Got Back," Luke Bryan's "Country Girl (Shake It for Me)" and Queen's "Fat Bottom Girls."
  • A treatment of Dolly Parton's "9 to 5" featured an unexpected and effective rap by Lundquist as well as all five singers beat-boxing together at the end.
  • And both of Foust's originals were big winners – the doo-wop-styled "Don't It Feel Good" and the aforementioned Johnny Cash-styled "Champagne Taste."

For that zoo concert, Home Free deserves a champagne toast.