Sentence:  In method as well as in theme this little anecdote with its details selected as much for expressiveness and allegory as for `` realism '' , anticipates a <WSD>kind</WSD> of musical composition , as well as a kind of fictional composition , in which , as Leverku^hn says , `` there shall be nothing unthematic '' . 
Meaning of the word marked with <WSD> tags:  a category of things distinguished by some common characteristic or quality