"Looking at some of the downloads that various people have sent in I have noticed that this feature is used quite a lot to good effect."

I think you have answered your own question.

I can't image anyone listening to music for all of five minutes that hasn't heard an artist modulate in a song - Whether singer or solo musician. Modulate, of course, means to shift from one key to another. Even to the untrained ear, hearing this change, (transpose, if you will) creates, not only interest, but also enhances the performance.

There were several good postings - Some, not so good.

Kudos, especially to The Leans and to Lloyd Ericksen, bruno123, Uncle Dave and Walter McLaren - Walter, yours is the best.

KN6 Guy