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 he announced in 1886 that La Scala would host the premiere of what was to become his penultimate opera , Otello .
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 .