"A Love Supreme, Part I: Acknowledgement" (John Coltrane)

I'd heard a fair amount of music by John Coltrane before hearing A Love Supreme for the first time in college.  I knew him as the fluid alto sax soloist on Miles Davis's 1959 masterpiece, Kind of Blue.  I knew his classic hard bop album Blue Train (1957) and its title tune by heart.
But A Love Supreme threw me upon first listen.  I sat there, waiting for a melody to reach out and grab me, or a catchy sax/piano/bass solo in the same vein as "Blue Train."  But neither showed up.  Instead, it was like musical mercury, flowing and changing shape from moment to moment, never content to stay in the same place.  
Frankly, I found it frustrating and turned it off.
But then I gave it a few days.  Something about it intrigued me, and it pulled me back in.  Especially the first part, called "Acknowledgement."  
Jimmy Garrison's soulful bassline and Elvin Jones's hypnotic drum pattern (which feels as if it might go off the rails at any moment, but never does) are the song's anchors, freeing up Coltrane and pianist McCoy Tyner to flow where they will.  (Although, I wouldn't go so far as to call this "free jazz."  There's still a lot of reliance on modality and unity of performance.)
Coltrane, who in the album's liner notes declares his newfound relationship with God, intended the album to be an expression and an extension of his faith.  He also alludes to his former dependency on alcohol and heroin and being able to kick those demons through faith—something the professor of my jazz appreciation music course in college told us led to this unbridled expression of joy and gratitude.
The key moment in "Acknowledgement" arrives after Coltrane plays a four-note pattern that rhythmically spells out "a-love-su-preme."  He plays it, over and over (more than 30 times), in twelve different keys before he begins the vocal chant: A love supreme / A love supreme / A love supreme...
At first blush, it just seems like Coltrane is noodling around, letting whatever ideas that are popping into his head flow through him.  I never really thought about it much until I ran across a 2012 NPR piece about the making of the album awhile back.  In the article, there's a bit of analysis from Dr. Lewis Porter, a Professor of Music at Rutgers University, who points out that, by playing the "love supreme" theme in all twelve keys, Coltrane is saying that God is everywhere and in everything.  
So what seems random actually is very purposeful and planned.
Selah.