Strangely enough, my introduction to this brilliant poem came from Dennis Hopper’s coke fueled rendition of an excerpt in Apocalypse Now. I wonder why Coppola chose If.
It's quite a decent poem and it lends itself to being read out loud. You can fiddle with the rhythm, volume and all sorts. Basically, it is extremely malleable, which is probably not a Eng Lit term but it works for me.