Josh Groban at Rising Star

Josh Groban takes a selfie on set of "Rising Star" on June 29, 2014.

 Tricia Traci/DCP

Josh Groban's new gig: juggling.

The singer dons a sleek suit and a pair of eyeglasses to host "Rising Star" on Sunday evenings, but also spends the week alongside a grand piano to mentor the weekend's upcoming auditionees.

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"I've grown kind of attached to them, just as people," Groban told The Hollywood Reporter after Sunday's episode, the second of the season. "My job is to try and find that thing that makes them unique. You can always talk about pitch and breath control, but really, I try to exterminate the things that I think are their weaknesses, and get them to really shine on the things that are great."

Of watching them audition live, he explained, "When they get out there, and the nerves kick in, you don't know if they'll do it, but it's always great when they do. ... The most difficult thing for me is watching that vote go up — my mic's not on, but I'm screaming backstage: 'Come on!' "

He said his most involved moments so far have been the East Coast almosts. Of Shameia Crawford's 69 percent vote, Groban said, "I was crushed. I was like, are you kidding me? Surely, there's one in there to get it."

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Crawford, a backup singer, later made it through during the West Coast vote, as did harp player Megan Tibbits — the first two saves of the inaugural season. "Last Sunday, it was pretty obvious who people liked and who people didn't. … Last week was like a dress rehearsal in front of an audience!"

Still, of his hosting duties, he said the scariest part about being on live TV is the demand "to expect the unexpected."

"Rising Star" continues Sunday on ABC.