Arrigo Boito (ärrē´go bô´ētō), 1842–1918, Italian composer and librettist. His opera Mefistofele (1868, rev. 1875), influenced by Wagner's music-drama, helped to bring about a new dramatic style in Italian opera. Its first performance, at La Scala, Milan, caused a riot, but it subsequently became very popular. Another opera, Nerone, was posthumously finished and produced by Toscanini in 1924. Many consider Boito's masterpieces to be the librettos for Verdi's Otello and Falstaff. He also was librettist for Ponchielli's La Gioconda and wrote novels and poems.