However the composer later conducted his Requiem there on May 25 , 1874 , and in 1886 announced that La Scala would host the premiere of his opera Otello . This dispute originated in a disagreement over the production of his Giovanna d'Arco in 1845 ; however the composer later conducted his Requiem there on 25 May 1874 , and in 1886 announced that La Scala would host the premiere of his penultimate opera Otello .