Complex sentence: Meanwhile Britten had been corresponding with his publisher, Boosey & Hawkes, about publishing "Noye's Fludde": several of its novel features, including the use of a large amateur orchestra, and specifically its use of handbells, were posing problems.
Split into simpler sentences: Meanwhile Britten had been corresponding with his publisher, Boosey & Hawkes, about publishing "Noye's Fludde". Several of its novel features, including the use of a large amateur orchestra, and specifically its use of handbells, were posing problems.