With the Glee kids gearing up for the school's production of West Side Story, there's musical theater magic in the air of the hit TV show. Of course, we knew Wicked Tony winner Idina Menzel was coming back for Glee's third season and how "happy" that makes Lea Michele...but we had know idea how epic their reunion would be! Menzel is once again guest-starring as Shelby Corcoran, the birth mother of Michele's Rachel Berry. The two Broadway vets sing this beautiful duet of West Side Story's "Somewhere" on next week's "I Am Unicorn" episode. Here's a delicious taste of the two powerhouse performers belting their hearts out. Takes your breath away, doesn't it? Tune in to FOX on September 27 to see the superstars sing it (as well as Darren Criss performing "Something's Coming" and Chris Colfer's take on "The Greatest Star" from Funny Girl)!