Hmmm, I don't think that the sheet music would fit on the frames, personally, as it does not apply to the whole game, so maybe we can use that as one of Theorin's Spell Card background. The (first) erhu and the brushes would look nice on the border, though, with the addition of 東方意地奴 for 'Touhou Ijiyatsu.'
Now to add some colors to it.