When you have a drill, everything starts to look like a nail you can hammer in with it~
Of course a craftsman introduced to a motor, is going to try and apply it to solve anything he can think of.
That said, this serge guy has some really weird ideas. Using a rotating motion to somehow power/play music? Usually you would just use wind magic directly to (capture and) play music and other sounds. Or maybe telepathy, if you are more well-versed in mental magics than wind magics.
You could even use earth-magic to power a diafragm, that in turn powers the air, if you are good at elemental magic but not wind. Or for fire mages, create some plasma (lightning) that in turn powers the air (tesla coil music).
His idea of powering a car with spinning magic is odd too. Normally you would use elemental magic directly, to apply the (reactive?) force that moves the car. But I suppose it might be quieter than the solutions wind and/or fire magic would need to impart forces. And the ability to stack x*y*z gears in a 3d box, for compounded torque, is an advantage over even the silent water-magic solutions (though earth magics ability to apply force on ENTIRE volume of car will always compound to more force... and more silent than both spinny-magic and water-magic solutions).