It’s been a few years since starting to look for a movie with this clip:
I remember a clip with ‘dancing flames / ballet of flames’; I remember an ‘up-beat’ bouncy melody – reminiscent of Disney perhaps, and the animation reminiscent of Fantasia (also perhaps). The clip shows a ballet of individual flames in a ‘chorus line’ all dancing and moving along, and from memory down a staircase (from left to right) – it is in colour, with the flames being in vivid red, orange and yellow, background rather dark-ish and indistinct, but inside a structure of sorts.
Maybe one day I’ll get lucky. It was such a great clip.