 About a minute from the end, the music suddenly switches to a new riff which also uses complex polyrhythms.The instrumentation is not as stringent as the first riff's, because in some parts, some instruments hold a sustained note while others continue the pattern.Aside from that, all instruments play the melody together, as was done for the first riff, including John Marshall furiously beating out the timing on drums and cymbals, bringing the music to a sustained climax.