Since the release of his 2001 debut album, Josh Groban has proven to wield a one-in-a-million voice. That being said, some of his finest work has been produced thanks to the contributions of second parties.

Groban, who's sold more than 25 million albums across his 17-year-career, has left audiences speechless with his performances of opera standards and original work, alike (as if anyone will ever forget the year of "You Raise Me Up"). Still, he's no stranger to sharing the stage, either — his career essentially began by performing a duet with Celine Dion during Grammys rehearsals in 1999. And the rest, as they say, is history.

Following the release of his newest album, Bridges, Groban will hit the road with Idina Menzel for what's sure to be a knockout tour. And his experience — which includes harmonizing with Kelly Clarkson, Nellie Furtado and Faith Hill, just to name a few — suggests an ensemble approach will go over just swimmingly.

Check out 10 of Groban's most memorable collaborations with pop artists, below.