Singer Groban poses at the LACMA 2012 Art + Film Gala in Los AngelesLOS ANGELES (Reuters) – After selling more than 22 million albums in the United States and becoming a staple in the classical music field, singer Josh Groban is embracing an edgier sound for his latest record, "All That Echoes," out on Tuesday. Groban, 31, put together a collection of covers and original songs for the album, including a rendition of one of his personal favorites, "Falling Slowly" from the movie and stage musical "Once." Under the guidance of veteran producer Rob Cavallo, the Warner Bros. …