Richard Wagner, it is said, looked down on "sonata form" as being too constraining. Roughly speaking, he objected to the long music passages with unchanging rhythm, with repeating cadences, that could be called algebraic. Specifically, he claimed he was not at all interested in Beethoven's pieces written in that style, such as the "Quartet in C Major", preferring those in which his predecessor deviated from it.
He referred to the portion of Beethoven's legacy composed in that style as the "sonata-form Beethoven," or "sonata Beethoven," which sounds kind of awkward in English.
Is there an adjectival form of the word "sonata" that sounds more natural?