Complex sentence: Don't Let It Die is a 1971 demo sung, written and produced by Hurricane Smith in the hopes that John Lennon would record it, that he decided to release himself after Mickie Most advised him to.
Split into simpler sentences: Don't Let It Die is a 1971 song by Hurricane Smith. It was a demo Smith had created in the hopes that John Lennon would record it, that he decided to release himself after Mickie Most advised him to.