A relatively long letter from Giuseppe Verdi to the Florentine vocal director Pietro Romani, reproduced here, indicates the tempos for individual numbers of his opera Giovanna d'Arco. Verdi had a general preference for quicker tempos. The letter also provides valuable evidence for the different roles of the vocal director (Maestro di cappella, Maestro al cembalo, Maestro della musica, Maestro delle opere, or Maestro concertatore) and concertmaster, who served as the orchestra's leader, suggesting an account of the evolution of divided direction of Italian opera into the modern situation of direction by a single conductor.
"A Letter by the Composer about "Giovanni d'Arco" and Some Remarks on the Division of Musical Direction in Verdi's Day,"
Performance Practice Review:
1, Article 10.
Available at: http://scholarship.claremont.edu/ppr/vol3/iss1/10