A little piece of a thing I'm writing: Before Frederick could argue with the cat he noticed a shift in the sounds coming out of the cats all around him. They were no longer meowing. Perhaps they never were. Frederick heard low, guttural baritones, high, shrill falsettos, wavering notes carrying over long and short periods. It was difficult for him to come to terms with this: the cats were performing a complex piece of written music. Have included the whole paragraph for context, the bold is the sentence in question. Does it seem awkward or am I over-analyzing?