Simplify the following text for a Grade 11 native English-speaking person.
Original: 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 .
Simplified: 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 .