Just a question/idea I was tossing around as I played a friend's fretless, would ear training be a quicker (albeit not necessarily easier) process on a fretless? I thought that maybe, given the necessity and the fact you have more room to improperly intonate. I am a beginner/intermediate bassist who does not know very much theory, nor can I identify keys etc.. yet. It is, however, something I am working on and am serious about learning. I play a fretted instrument and he offered to swap with me for a few weeks if I wanted to play around on his fretless (he has other basses so it's not a very significant sacrifice to him). Any thoughts, should I grab it for a few weeks and work on theory to really drive the points home and try to "get my ears right"? I'm all for it if it would help, I would rather pass and not bother if it wouldn't.