Whenever lead is being played the lead guitarest is hitting several notes out of all the notes that the guitarest is hitting on lead how do you know wich note he is hitting to play rythm with, like if he is hitting A A# and C really fast how would you know wether to play rythm with A or A# or C??? Also when the rythm guitar player is playing bar chords fast where you cant get a lead going with one rythm note, how do you know what rhythm chord the guitar player is playing to play the lead to, For example listen to kirk hammet's lead on the song "Master Of Puppets" James hetfield is playing rythm wich is changes chords fast and kirk hammet is playing lead to it, i was wondering how you would know what note of lead to play to that fast rythm playing?

Sorry about all the questions everyone, but i have no one i know that knows any of the questions i want to know so i am asking them all here, thanks for the answers!