whether Show Of Hands are more HTML standards-compliant than Bellowhead

ROLF! At least that one's easy to work out. Whether it matters or not could go on for ever (who does this World Wide Web Consortium think they are?)

Getting back to the subject: anything that requires you to first develop precision and co-ordination in order to make a sound that isn't unpleasant is definitely harder. Fingering and so on is largely a matter of developing the muscle memory.

Any fretted instrument is pretty easy. I always used to tell my beginner guitar students that as long as their fingers are holding the strings down in the right places, their E chord sounds just as good as Eric Clapton's. Unlike a learner violinist who will take months to get past the strangled cat stage.