Don Mclean has steadfastly refused to explain the 'meaning' of this iconic song, but that hasn't stopped others! Here is one suggestion.
"While playing a concert at the Altamont Speedway in 1968, the Stones appointed members of the Hell's Angels to work security (on the advice of the Grateful Dead). In the darkness near the front of the stage, a young man named Meredith Hunter was beaten and stabbed to death -- by the Angels. Public outcry that the song "Sympathy for the Devil" had somehow incited the violence caused the Stones to drop the song from their show for the next six years. This incident is chronicled in the documentary film "Gimme Shelter".
It's also possible that McLean views the Stones as being negatively inspired (remember, he had an extensive religious background) by virtue of "Sympathy for the Devil", "Their Satanic Majesties' Request" and so on. I find this a bit puzzling, since the early Stones recorded a lot of "roots" rock and roll, including Buddy Holly's "Not Fade Away".
'And as the flames climbed high into the night
To light the sacrificial rite'
The most likely interpretation is that McLean is still talking about Altamont, and in particular Mick Jagger's prancing and posing while it was happening. The sacrifice is Meredith Hunter, and the bonfires around the area provide the flames.
(It could be a reference to Jimi Hendrix burning his Stratocaster at the Monterey Pop Festival, but that was in 1967 and this verse is set in 1968.)
'I saw Satan laughing with delight'
If the above is correct, then Satan would be Jagger."
https://www.bbc.com/news/magazine-32196117
scroll way down)
