I think it's jazz. It starts with a bari sax doing a simple rythm:
pa--- pa--- pa--pa --para/pa--- pa--- pa--pa --para (it repeats for a long time)
i wrote it like its a 4-4 score and each "-" would be a semicuaver and i left a space between each pulse
afte these ryhthm repeats a couple times I don't know if those are trumpets or horns (definitely brass) that start making arpeggios some of them of the first three notes and some of all
I just love how the song starts but I can't find it anywhere.
I tried to describe it as exactly as possible.
Thank you very much.