What is the fine-grained topic of the following text: He has also sung Mahler’s Songs of a Wayfarer and Rückert-Lieder, Haydn’s Lord Nelson Mass, Duruflé’s Requiem, Handel’s Messiah, Fauré’s Requiem, Dubois’ The Seven Last Words of Christ, Mozart’s Missa brevis in F Major, and Mack Wilberg’s Requiem. Only return the topic.
Classical musical pieces performed by a particular singer.