so...i've been coming up with some riffs and wanted to back them up with a second guitar part to get that a7x sound like on the intro to "m.i.a." How do i do that? I know the second part isn't an octave lower, more like half? is there a pattern to writting the second part lower/higher?
There are a few ways. You can make the second guitar play a 3rd lower, a 5th lower, an octave lower, etc. Harmonizing with a guitar playing a 3rd lower or octave higher/lower sounds nice. The octave can get annoying if used alot though.