I think I may have discovered a way for dedicated fretless players to play in tune ALL the time.What you do is get some thin wire from your local hardware store and then,using a ruler,mark the positions on the neck where the notes should be.Then,using a hacksaw,cut some fine grooves in the neck from side to side just slightly up from the note position.then using some glue,stick pieces of the wire into these grooves,and cut off the ends,using some scissors.Using your fingers,press down between the fillets of wire,and ,hey presto,you will hear a note that corresponds to the note that you wanted in the first place.Using your eyes,look and make sure that the fillets of wire are straight.This also results in making the leg of the guitar look much more interesting.