[J.C.] Bach wrote it for oboe and strings in 1765. It’s in his middle period, not as classical as earlier works and not as personalized as later ones.

I’m feeling a bit stupid … J.C. Bach’s earlier music was classical and his middle period is not so classical and then there’s the personalized later period? I can barely remember my music history, but this just seems off to me. I’m going to guess, though, that maybe someone out there can help me understand. Please?