Complex sentence: Ironically, after recording, Evans was utterly unwilling to release it, believing the trio had played badly; however, upon hearing the recording, he changed his mind, and later thought of it in very positive terms.
Split into simpler sentences: Ironically, after recording, Evans was utterly unwilling to release it, believing the trio had played badly. However, upon hearing the recording, he changed his mind, and later thought of it in very positive terms.