Midi files:
https://bitmidi.com/uploads/83417.mid (this has the vocal line transcribed for the alto sax and sounded none too bad playing on TTS1 in Cakewalk);
More versions from the same site https://bitmidi.com/p-floyd-the-great-gig-in-the-sky-mid;
https://www.midiworld.com/download/3447
http://urukhai.tripod.com/midi.html
https://bitmidi.com/p-floyd-the-great-gig-in-the-sky-mid
Multitrack (not the original, but a starting point): https://songgalaxy.com/Multitrack/Pink-Floyd/The-Great-Gig-in-the-Sky/RE31047.html