I do a lot of tune teaching and workshops on fiddle tunes etc, at festivals with the Boat Band ans so on. We do the same as Kathryn said, teach the tunes slowly by ear, and dish out sheet music at the end of the day if anyone wants an aide-memoire. If you hand out sheet music at the start, the good readers read it straight off, and then always seem to be saying "Next?". I would much sooner spend a long time getting it people to learn it carefully by ear and finger and brain, not by readinfg. Then it sticks, and it is a nice collective experience for everyone.