One where the performer is the centerpiece of the action and the music IS the event, one where the music is a backdrop and the performer's stage management skills are just as important. Lyra might be a third - the minstrel who organizes participatory music. (Well, someone's got to get the cast ready for musical numbers...)
What got me thinking about it originally was a series of D&D-style "deity descriptions" I did after seeing a few alicorn pics. In order to differentiate the various "music" characters, I did this:
Octavia The graceful cellist Demigod Alignment: LN Domains: Creation, Law, Artifice Portfolio: Dancers, classical music, ensemble musicians, orchestrae, professional musicians
Of the deities of music, Octavia's approach is the grandest. She enjoys and promotes music where the performer's skills set them apart, whether as part of a grand orchestra, a chamber ensemble or a solo. Professional musicians revere her, and her symbol has become incorporated into the notation of conventional music.
Vinyl Scratch DJ P0N-3 Demigod Alignment: CN Domains: Creation, Chaos, Trickery, Charm Portfolio: Modern and electronic music, arrangers, DJs, nightclubs, sound recorders and edited sound
Vinyl's take on music is that it should be a background to events, not the centre of attention - at least not for their music. Her worshippers cultivate a stage image that enhances the experience, but are content to let the music do the talking. They rarely make the music themselves, but often arrange it for consumption or otherwise provide it.
Lyra Heartstrings The Harper Demigod Alignment: N Domains: Creation, Community, Dreams, Travel Portfolio: Folk music, collaborative music, amateur and casual musicians, bards, minstrels
Lyra is the deity of those for whom music is a hobby and a pastime. When a village meets for a festival, she will be invoked - and the same for a small group of friends wanting to make music for fun. The few professional musicians who follow her are bards and minstrels, who travel the land carrying their songs and organizational expertise to new places. They can often get a whole town singing along to their latest tune. This wanderlust also makes her the patron of explorers who discover new lands and peoples. An old story tells of her love for a mortal, but the end is missing.
Thanks, I'm fairly proud of it - I think the Pantheon holds together as an actual one, which is to say that there's a deity for enough things. Gilda, for example. She's basically the deity of loose cannons and mavericks, which is to say mercenaries, loners or the kind of police who get their own TV shows.