I don’t know if there has ever again been as happy a combination of rock with “Latin” (nowadays we say “Afro-Cuban”) elements as on the first two Santana albums. These songs have tricky syncopated bass lines and complicated polyrhythms in hand percussion (that’s the “Latin” part) but colossal rock thrust at the same time. What holds it all together, besides the composers taking advantage of that ripe historical moment when primal riffs could still be plucked from low branches, is that the players are all super-hot. Their energy sweeps away genre limitations like a 100-year flood sweeps away a puny dam.
This lively music is strangely not for dancing. I don’t say it’s impossible to dance to Santana—indeed, I believe I saw a woman gyrate to “Soul Sacrifice” in the Woodstock movie—but a typical Santana song would derail your dance pattern every minute or so with a profound rhythm shift; you would risk injury. For the seated or solitary listener, this is a huge plus. Shifty music can be much more viscerally compelling than anything doggedly metronomic.
As a one-track exhibit of Santana’s powers of shiftiness I like “Incident At Neshabur.” It has a fast Latin intro section of eleven measures and then abruptly a HUGE (now we say “arena”) hook using the I, flat-III, and IV blues-rock chords, sounding like one of the first things you’d do on your new electric guitar (while the figure’s intricate finish in its fourth measure is something you’d try to master for months). This hook does have Latin percussion and a triplets pattern overlaid, but it’s fundamentally One-Two stompable as well. And then we’re on to other rhythms, including a surprisingly slow and quiet samba, and contrary to the rules of rock we end with a peep not a bang.
Of all the neat shifts on Abraxas, the one that impresses me most is in “Black Magic Woman” at 3:36. It comes just nine measures after a previous shift at 3:20, so it hits like a hypershift. It slaps you left-right left-right BAM BAM BAM BAM (sorry to be flirting with kinky sadomasochism here) to completely take you over, depriving you of any momentum of your own and yet bestowing a greater force upon you as long as the special moment lasts.
I bet people on the salsa scene will say they have the best of all worlds, the interesting “Latin” complexities and tricks in the music meshing with intricate and energetic dancing. That’s too hard for me, though. I’m a listener. In my kitchen, in my car, nothing in recorded music shakes me harder or deeper than this early Santana.
 In an interview on NPR, Bobby Sanabria says it’s a celebratory bembe rhythm.