Okay, so I've been turning the idea over in my head for a LARP based on the Phonogram comics, to be run "under Masquerade," as it were, during the Spouse's DJ nights. Here's the basic idea:
Each phonomancer would have a schtick - the way s/he accumulates musimagickal energy; two tricks - the effects s/he can produce with the energy; and one ritual - a long procedure requiring preparation that produces a longer-term or more intense effect.
Schtick - [Canonical] Kohl's is analyzing a song; Penny's is dancing. [Non-canonical] Singing (either along with a song or performing), Playing an instrument, Critiquing a song/piece, Writing music, Building a mixtape/CD/playlist
The Nudge - Implants a simple suggestion for someone to do something that is not outside their normal realm. Examples from the canon: Kohl and Penny both do this to get into clubs by suggesting that they're on the guest list. Won't make someone do something they wouldn't normally do, i.e. serve you a free drink. Phonomancers get to resist (if they win at rock-paper-scissors, they can ignore it).
Glamor - Makes the phonomancer appear more attractive/intelligent/assertive/etc. than they actually are. Pick one attribute to enhance; Glamor (appearance) and Glamor (trustworthy) are two different schticks. Penny has this one in spades; The Girl appears to also have it, and Kohl might.
Lay Down The Whammy - Hexes the target with minor bad luck, such as running into someone they dislike briefly, making their record skip, spilling their drink, etc. Seth does this to himself in the canon.
Blink - Makes the phonomancer unnoticeable to the target(s) for a few seconds. This is more of an SEP field than true invisibility, more useful for blending into a crowd or a quick slip out the door than picking someone's pocket or even stealing their drink.
Spirit-singing - Allows the phonomancer to speak with a spirit resident in a specific location. This does not summon a spirit that isn't already there. Note that if a spirit decides to speak with a phonomancer (as the memory-She does in the second book), they can do so whether the phonomancer has this trick or not; this is required for the phonomancer to initiate the contact.
Rituals have to be developed individually: the Memory Realm ritual, various grimoire-writing rituals, the self-rewriting ritual that Emily used on herself, the more potent version of the Nudge Kohl uses on the Kenickie fangirl in the first book, etc. It's unlikely that these will be used in-game, and they'll all require items of significance - the 45" with the pentacle on the back, the makeup for the Memory Realm ritual, etc.
Everyone starts with enough mojo for two tricks, and can gain back 1 mojo by performing their schtick for 10 minutes of game time.
Anyone interested? Hit me up with character ideas if you are, and I'll see about fleshing out something resembling an actual system.