Josh Groban is fulfilling his childhood dream of starring in a Broadway musical. The thirty-five year old is currently rehearsing for opening night of the new production ?The Great Comet of 1812.? The last time Groban appeared in a musical was in a high school production of ?Fiddler on the Roof.? The singer attended one semester at Carnegie Mellon?s musical theater program, before dropping out when Warner Brothers offered him a record deal. Groban said of his first Broadway previews, ?it was more emotional for me than I thought it would be.?