What's going on here? (WARNING: Sweelinck harpsichord content)

[XB-70 Valkyrie]

Some internet person wrote in the comments section that the diagram on the right is a musical gamut illustration. What is it showing? I see the treble, alto, and bass clefs with a different note highlighted every few seconds. Is this a form of modulation? Scuse my ignorance...I'm not really strong on music theory.

https://www.youtube.com/watch?v=DgEdln2KSlA&list=RDMMDgEdln2KSlA&start_radio=1

[DaveF]

Not modulation as such; the piece is a hexachord fantasia, so built on the unchanging rising and falling scale pattern ut (or doh), ré, mi, fa, sol, la, which is heard, as you can see from the gamut, at 5 different pitches: in the bass, tenor and treble on F (F, G, A, Bb, C, D), and in the bass and treble on C (C, D, E, F, G, A).  As you can see, all the notes of the 'C' hexachord fit happily into F major, so the piece doesn't need to leave its F major home key in order to accommodate them.  So I suppose you could argue that the hexachord itself modulates (although that's probably not the word Sweelinck would have used), with sol in the F hexachord becoming ut in the C one and vice-versa, whereas the music, excepting the odd cadence into the dominant, remains pretty well stuck in the same key throughout.

The notes on the gamut light up when that particular degree of the particular hexachord is being played - sometimes they're easy to hear in long notes in the bass or treble, at other times they're hidden away amid the figuration or merely implied by the harmony.

If you want a hexachord fantasia that really does modulate, there's one by Bull in which the hexachord is heard on every semitone of the scale, which means either that equal temperament was invented earlier than we think, or that the piece must have sounded staggeringly weird - as it still does, in fact.

And thanks for the link, BTW - great piece, and the little gamut is fun, especially at the end where two hexachords start going in contrary motion.

[XB-70 Valkyrie]

Thanks for the summary! I love that piece, and it is indeed a very nice sounding instrument in that video.

[Pat B]

Interesting. Thanks to both of you. I've been meaning to look up the Bull mentioned by DaveF but haven't gotten around to it yet.

[XB-70 Valkyrie]

This is probably wrong in all sorts of ways  but in the same vein (or at least the same inferior vena cava) I also like this one!

https://www.youtube.com/watch?v=jyhZaSso414&start_radio=1&list=RDjyhZaSso414

[Marc]

Interesting. Thanks to both of you. I've been meaning to look up the Bull mentioned by DaveF but haven't gotten around to it yet.

https://www.youtube.com/watch?v=hpDkbRpxwKw