"Blue Train" (John Coltrane)

The album Blue Train (1957) wasn't John Coltrane's first time as bandleader; he'd recorded his solo debut, Coltrane, earlier that same year.  But Blue Train is where his artistic genius truly begins to shine.  Every solo flows so fluidly, it's as if the music is being poured into his body and is finding its outlet via his horn.  It's where you get the first real glimpse of Coltrane's hotline to the divine.
The album's title track remains one of my favorite jazz recordings of all time.  I first heard it on a Blue Note Records compilation album called The Best of Blue Note (1991), and I loved it from moment one.  As the name "Blue Train" implies, it's built around a basic 12-bar blues structure.  But it's what Coltrane and his band do with that structure that keeps the song from being anything but basic.
In short, the song is a journey of melody and virtuosity.  It's an aural representation of a passenger train trip: the engine easing out of the station and slowly gaining speed as it rolls past the graffitied backsides of tenements before finally rocketing into leafy suburbia, steady on its trajectory to the next metropolis.
It opens with this melancholy, minor-hued riff, which resembles a train whistle.  It remains in a minor key as Coltrane goes headlong into his excellent solo, but then as soon as the locomotive is up to speed, he shifts from minor to major, subtly creating this feeling of propulsion.  A few bars later, drummer Philly Joe Jones abandons his swing for a fast shuffle, which sounds like the click-clack of metal wheels on tracks.  Along the way, Coltrane's consummate sidemen (in order of soloing: Lee Morgan, trumpet; Curtis Fuller, trombone; Kenny Drew, piano; and Paul Chambers, bass) take their turns painting the world that's flying by the train windows.  (If I had to pick a favorite solo, it actually would be Fuller's.  It's mellow yet nimble—more nimble than I ever thought a trombone could be.)

"Moanin'" (Art Blakey & The Jazz Messengers)

I really didn't know all that much about jazz when I bought my first jazz album.  It was a compilation by Blue Note Records called The Best of Blue Note (1991).  Although in time I'd come to recognize that the album consisted strictly of "hard bop" tunes from the late 50s/early 60s, I had no idea how to categorize it when I first heard it, sitting at a listening station in our local mall's Camelot Music store.  I only knew I liked the funky, bluesy feel of the songs.  And one track stood out in particular: "Moanin'" by Art Blakey & The Jazz Messengers, taken from the 1959 album of the same name.

"Moanin'" was composed by Bobby Timmons, the pianist for The Jazz Messengers, circa 1958/9.  The song originated from a bluesy little 8-bar improvisation that Timmons would play between numbers at shows.  Although Timmons regarded the riff as a throwaway, the band's saxophonist, Benny Golson, heard something more and encouraged Timmons to add a bridge section and develop it into a full-fledged song.  Still somewhat doubtful about the composition, Timmons and his bandmates debuted "Moanin'" in late 1958 at the 502 Club in Columbus, OH.  To his surprise and Golson's satisfaction, it was a huge hit with the crowd and instantly became a hard bop classic.

So what exactly makes the song "hard bop"?

Primarily, it's the rhythmic approach.  Unlike cool jazz of that same era, which tended to be lushly orchestrated/arranged and supported by soft, subtle rhythms often played with brushes on snares, hard bop was brassier, bolder, and punchier.  It took its cues directly from gospel and blues.  In fact, the gospel influence—particularly in the call-and-response interchange between Timmons and the unison playing of trumpeter Lee Morgan and Golson on the choruses—is undeniable.

Every solo on this song is executed perfectly, and the level of ESP is amazing.  Case in point: my favorite moment comes around the 3:00 mark as Morgan wraps up his funky turn.  He plays this short line of notes, kind of as an afterthought, and Golson intuitively picks up on the same theme, using it as a segue into his own inventive solo.  It makes me smile every time I hear it.