[hedzeppelin]

Hey, John...whatever works for you is cool. I don't believe in all that music theory stuff, either. I don't read music, I totally improvise. However, knowing scales and chord construction has helped me expand my playing.
And yes, anything is possible in music. You can play anything that you want. If the key of the song is in "A" and you want to play the solo in
D#, it's totally possible.
However, how good will it sound?