There is also an issue about changing the sounds of each guitar. I remember recording a few songs with a friend and we started off, coincidentally, both paying Takamine guitars that, although looked different, had identical pick up systems. Well after a couple of songs it sounded to us like there was only one guitar and it was all a bit flat and uniteresting. So I switched to a Guild with HBs and the studio tech put some tremelo on my guitar. Problem fixed - we had a much better sound blend. That became what we did for every live gig after that day. (BTW - the sound guy went back into the first two recordings and tweaked the sound of my guitar with tremelo and EQd it to sound like the HB pickups.)