i see that during some scratching segments, theres an open circle before the scratching zig zags 
 
what do you on them?

I don't think you're supposed to let go.

Still I think it grants you a small window of forgiveness if you do let go.  I'm not sure - it usually goes by so fast that I had no idea what I did, but I seem to get it right.  It feels like I do some specific thing to separate the circle from the scratch.  I'm not saying letting go is the correct thing to do though since that would be the same thing as a tap right before a scratch which they already do.  It may just be a held tap up until the scratch, but the usual held tap icon blending into a scratch probably looked weird?

It's like the elongated scratches, only it has a tap instead of a single-directional scratch.

" I don't think you're supposed to let go. "

Okay, if it works. Maybe that's how Afro gets all his high scores :P