There are only 12 notes in Western music. Eastern music can have more than that. There actually is a 43 note scale:
http://en.wikipedia.org/wiki/Harry_Partch%27s_43-tone_scale
Steve is correct though, in Western music you are never too far away from the correct note. As a lead guitarist you learn either one of two things when you hit a wrong note, either bend up to the right one or play the wrong note a few more times so people will think you did it on purpose. If anyone asks you about the wrong note then you tell them is was the correct note, you were in a different mode.