Complex sentence: In Ferrara, the center of avant-garde activity, he doubtless heard the madrigals being composed for the d'Este court; however, his own style remained conservative and became simpler and more refined as he aged.
Split into simpler sentences: In Ferrara, the center of avant-garde activity, he doubtless heard the madrigals being composed for the d'Este court. However, his own style remained conservative and became simpler and more refined as he aged.