Personally I think Octavia should have her way with Sweetie Belle first: teach her the basic techniques and the classics until she has it down cold. Then DJ can get the little unicorn into freestyle/rap and working the crowd when Sweetie vocal talents are already second nature. But I can see the other side too. I'd love to see an "Epic Rap Battle of Equestria" between the young mares to decide who gets to tutor Sweetie Belle first.
It's a fun drawing overall, and though sparsely decorated I like the flourish of color above the main window then each's one wall hanging. Interesting layout and colors for the small place, but then again it could just be their practice room. Though the awards are on Octavia's side I suspect that they're actually Vinyl's just because they're microphones, but I won't over-think it. Too much.
Sweetie's shocked and confused face is perfect. Let's hope they don't rough her up too much with their tug-o-war.
Well that's just another subplot. See, while this is going on, Lyra's off recording a duet album with Sapphire Shores, and various shenanigans ensue when Bon Bon thinks it isn't such a hot idea since Lyra's harp isn't quite accommodating for hooves yet, and she trails Sapphire's tour bus to try and sabotage the recording process...Or something incredibly far fetched like that
I hope this is the plot of the episode when Rarity and Octavia have that duet. It would go like:
Rarity notices Sweetie Belle's talent in singing, and sets her up with music lessons by none other than Octavia. However, Rainbow Dash (and by extension, Scootaloo) find that far too prissy, and instead call for Vinyl Scratch to do the music teaching.
As neither Vinyl nor Octy have a protege, they both want Sweetie Belle to become that. Meanwhile, this whole conundrum causes Sweetie Belle much grief.