I'd have thought EVERYBODY here would have learnt to spell Vaughan Williams by now. It gets very boring seeing the same silly mistake repeated and corrected over and over again for years.

The shift to complex arrangements is one that has been made in many parts of the world - there are many folk music genres in Asia, Africa and Polynesia that are never performed except by groups, and some cultures (Georgia, for example) that have practically nothing except arranged multi-part music and seem to have been that way for centuries. The West's version of that is the rock band, and that's the tradition the folk arrangements come from.

Most of the Scottish dance repertoire was intended from the outset to be played either by a full dance band like Nathaniel Gow's, or with piano/harp accompaniment, or at least with a cello doing the bass line. It just doesn't sound right as a solo melodic line.