Notes are in the box, as it happens, musical notes -- that is, if the box is a Shruti Box, a sort of preset background accordion. Looks a bit Subcontinental to me.
Having fallen over the site, I was going to make a snarky comment about it being an exotic, foreign musical instrument that even a clueless hipster could play; but after listening to the haunting little improvisation linked to at the site, I'm inclined to give it a break. It's pretty darned kewl -- and way better than handing the lead signer a tambourine.
PS: I was also intending to make some remark about the device's similarity to the drones of bagpipes still not being a serious threat to the Scottish dominance of that fearsome weapon of war; good thing I had second thoughts, since (of course) India has bagpipes of her own, with a long and ancient lineage.
This gives rise to another question: what odd quirk of English character is it that leads 'em to go ruling over nations of canny, thrifty bagpipers with a high degree of mechanical and mathematical aptitude and little inclination to surrender? "Oh the haggis is well enough but I'm minded to have a curry now...." Gads.
(Or is it all an elaborate, satirical warning of the dangers of stereotyping and over-generalization? Still, it's tempting to wonder if we owe the Industrial Revolution, seminal work on microwaves and huge swathes of mathematical physics to a desire for a more-varied diet and finding someone who could do something about the drains.)
2 months ago