Gustav Mahler called his Fifth Symphony a "foaming, roaring, raging sea of sound," and the piece serves as a love letter to the composer's wife that he wrote in their first year of marriage. Tonight at 7:30 at Severance Hall, the Cleveland Orchestra plays it along with Neuwirth's Masaot/Clocks Without Hands. Guest speaker Michael Strasser, professor of musicology at Baldwin Wallace University Conservatory of Music, speaks about the piece in a pre-concert talk that takes place an hour before the performance begins. It's free for ticket holders. The program repeats at 8 on Saturday night. Consult the orchestra site for ticket prices. (Niesel)