That would be a great idea for a Season 4 episode, and it would finally give them a reason incorporate Vinyl into a story (as opposed to the brief background cameos she's had thus far). Plus we'd finally get to hear her voice.
I could see this working for an episode; Sweetie Belle trying to find what she's good at, is on the right track, works with Vinyl Scratch a bit, Rarity blowing a gasket at Sweetie Belle's new look, it's wonderful!
Oh horsefeathers... Rarity's gonna have a field day, once Sweetie Wubs (this name made me laugh so hard...) gets back from her DJ lessons with DJ-PON3.
POSSIBLE FANFIC: Sweetie Belle learns of her natural talent with WubWubWub'ing and putting down the bass. Her talent is great enough to grab the attention of Vinyl Scratch. Possible Cutie Mark Acquisition? Could Sweetie Belle's electronic skills be due to a secret that lies 'skin-deep' ?