Based on 24 poems from the medieval tome Carmina Burana, Carl Orff's Carmina Burana is a scenic cantata that dates back to the 1930s. The work begins and ends with the well-known and slightly mystical "O Fortuna," and is mostly based on the idea of the turning of the wheel of fortune. The Cleveland Orchestra, the Blossom Festival Chorus and Cleveland Orchestra Children's Chorus all take part in the massive production, tonight at 8 at Blossom Music Center. Consult the orchestra's website for information on ticket prices. (Niesel)