As a musician, I loved to see so many music-related clues and entries! VALERO/EMACS kept me from completing it on my own. And I'm not sure if there's something to the starred entries that I didn't quite catch onto...
I'm a musician too! So the themed clues were worded so that they fit with both the full word (e.g. CONSTANTINE) and the 'music piece' (e.g. Constant in E). Thus, Continuous (Constant) Con Man (Constantine) Continuo (type of music piece).