Ritchie Blackmore called that "having to transcend the boundries"Yeah I know what you mean. On those days there's this negative synergy between the physical sound of the amp/room and my perception of my playing.
It's like trying to crack a code that you already know but the combination is still elusive.
Then there are those magical days where you are completely in the zone.
I haven't been able to make that happen each time and maybe I'm not supposed to force it to happen but sometimes I think we have to go through some of the bad gigs to get to the good ones.
Had a gig yesterday and I just didn't feel it. The tone coming from the amp was weird (odd acoustics in the room) and I played like crap.
I hate it when that happens.