The theme song from Rocky, written by the score’s composer Bill Conti and featured in an iconic training montage (warranting many inclusions in parodies). The horn intro in particular plays over the title sequence of all but one of the Rocky films.
https://www.youtube.com/watch?v=MR6FXpaECY8
Trying hard now
It's so hard now
Trying hard now
Getting strong now
Won't be long now
Getting strong now
Gonna fly now
Flying high now
Gonna fly, fly, fly
Gonna Fly Now was written by Ayn Robbins & Carol Connors & Bill Conti.
Gonna Fly Now was produced by Bill Conti.
Bill Conti released Gonna Fly Now on Sat Feb 28 1976.