This song from the film is in the second half, where our Jesus "vents his feelings about his imminent death". It's a good display of his vocal range (you can hear him hitting those high notes, like Ian Gillan did a few years before him). And there is a surprisingly funky bass line throughout.
Song : "Gethsamane (I Only Wanted To Say)"
From the LP "JESUS CHRIST SUPERSTAR Original Motion Picture Soundtrack" (MCA) 1973