So reacently im transcribing blood and thunder by mastodon, everything goes fine until the bridge harmony. Its this lead line type of thing where both of the guitar players players play harmonized in 3ds in phrygian (thats whats it sounds to me). I can't just not find out what the higher harmony (the one im going to learn) is. The two guitar is like fighting each other to get my attention, and its annoying as hell... So how do you guys ''seperate'' the two leads when something like this happens?
2 options -

1. Try going between the parts and see where the melody gets carried; it doesn't always stick to one guitarist, sometimes one will be playing the melody and the other the harmony, and then half way through the solo it switches. Keep following the melody until you have a part down that retains the sound of the original when played without a second guitar.

2. Be creative and find a way to play both parts at once! Hard to do for fast licks or when they're not harmonizing single notes, but doing this for hooks that aren't too fast and are there to create a catchy melody isn't usually too tough. Usually.
Well, if you know it's in thirds, just find one of the lines. Then try it a third up and a third down and see which one is correct.