Well what I'm thinking for the wizard is a guitar or a bass. The first idea was as a scion of Ogma the celtic god of poetry and luange.
I actually did something similar for my character for our game. He's an exiled member of an alternate order of bardic practitioners called the Taliesen Orchestra. Taliesen is the Welsh god of Bards and, in some legends, was the bard in King Arthur's court. High concept - "Jukebox Hero - He's got Pentacles in his Eyes)
The biggest issue is the concept of supernatural power and tech, especially modern, electrified, instruments, and how power interacts with technology. Basically me and the GM agreed that there would be some ways to get around this. First, the use of vintage instruments and equipment (basically nothing with a microchip and pretty much the older the better) My character uses a '75 Rickenbacker 4080 doubleneck 4 string bass/6 string guitar and a late sixties amp. The other safeguard is in the form of two warded leather wristbands that pretty much mute and contain the flow of supernatural energy (similar to the amulet Harry wears while in hospitals to help prevent him accidently blowing up sensitive medical equipment). Even with those safeguards in place, there is always the risk that the power will overflow and end up damaging the equipment (up to the GM's discretion) which IMO is a fair trade off in order to be a rock star wizard. ^_^
So, I've made it a point that my character was also trained in the fiddle. Basically, an alternate focus item that acts as a back-up when my character A.) Damages his gear, B.) Can't lug his gear around , or C. Can't power his gear.
In terms of actual powers, basically he had full blown evocation with a level of refinement( to account for all the focus and enchanted items he needs) with no ritual or Thaumaturgy. Basically the instruments act as a focus item, the music acts as a level of mental protection to help focus the thoughts on the effect he wants to produce. So, basically two Symphonomancers can use the same piece of music and produce different effects, it really depends on how the music shapes their thoughts.
Me and my GM also created a stunt called "Magical Performance" which means that whenever I play music, I roll against my Discipline instead of my Performance skill, since my music and magic are so interlinked.
Sorry 'bout the info overload.