I have been watching orchestral videos, the score flow, studying the structure and generally listening to Boléro more than is perhaps healthy, since yesterday. That snare ostinato apparently seeped in and took control of my brain, man. (Also, that poor snare drummer, man. 😝 )
It is fascinating to watch the extremely slow crawl through orchestral instrumentation, and how different the melody sounds when played by which leads and then which combinations later on.
And it goes on, one might say... INTERMINABLY.
There is only FINALLY a modulation, a minute before the end!
The "ending" begins in earnest 2 minutes from the end, when Melody A is played only once (instead of repeated with an instrument and volume change), a modulated Melody B, then 30s of "conclusion"
At its very loudest