It's even more incredible than just the woods and the music.
Bear with me folks and try not to
until after you read all of this...
I have watched it several times over now, getting it all figured out. That xylophone is remarkably designed. Just look at what they had to take into consideration when they designed it:
As I am sure you all recall (those who have studied high school or college physics) that the small gravitational constant (relates to dropping an object close to earth) is approximately 32 feet per second per second. Just to clarify, for example, if you get on your roof and drop a ball to the ground, the speed is not constant. The ball travels at a faster and faster rate (until it is stopped by the ground).
Back to the xylophone... from all views it appears to be installed at the same slope at all points. Since it is sloped, the constant would be somewhat less than 32 feet per second per second but one would still expect the ball to accelerate. With the keys mostly equally spaced, the music would be expected to get faster and faster, right?
But it moves along fairly smoothly. There is a V shaped component between each key, supposedly to keep the ball on the track to the bottom. It isn't until towards the end, looking back up the track, that you can get a good look as the ball hits each of these V thingies, it rocks around a little as it moves forward. The amount of time it does this depends on the shape of the inside of the V. I think they are carved to be a bit rounded (and not all the same) to put a bit of English on the ball, so to speak.
Other places also slow the ball down; the larger, more platform type Vs should reset the ball to the same starting speed as at the top of the xylophone.
I hope you all are still awake.... I need to get back to washing dishes and cleaning the floor
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