Complex sentence: He was initially dubious about Rameau's new musical style- "Rameau had the misfortune to know more about music than Lully"// /, but this soon turned to enthusiasm and a desire to work with the composer.
Split into simpler sentences: He was initially dubious about Rameau and his new musical style, writing He is a man who has the misfortune to know more about music than Lully. However, on further acquaintance, his attitude towards Rameau and his music turned to enthusiasm and a desire to work with the composer.