My Little Pony: Friendship is Magic - Octavia's father!?

That is quite possible. However, take the following factors into consideration:

1.Octavia and Vinyl both like music.

2. The pony in question looks like he could be 'Tavi's father.

3.He is also a unicorn.

4. His music-related CM also resembles Vinyl's.

My conclusion(headcanon): Octavia and Vinyl are sisters, but Vinyl is the black sheep of the family because her musical interests are so radically different from those of her refined, sophisticated family.

Kind of throws a wrench into all the R34 of the two of them, doesn't it? Or maybe it just incentivizes it even more, I don't know anymore…