Shades of Joy was a short-lived supergroup of a bunch of hippies jamming out some funky, trippy, and soothing grooves on a plethora of instruments. It's a mystery who was actually in this loose-knit group but supposedly Jerry Garcia was part of it. If you notice on the cover it says "arranged and conducted by Martín Fierro". After a little research I learned that Martín Fierro was a saxaphonist who played with not just The Dead but also The String Cheese Incident, David Grisman, Yonder Mountain String Band, Quicksilver Messenger Service, Sir Douglas Quintet, and the Allman Brothers, just to name a few- holy cow. Sadly, Matín Fierro aka "The Meester" passed away just last year.
El Topo is a concept album covering the soundtrack to cult director Alejandro Jodorowsky's film with the same name.
If you arn't familiar with Jodorwsky's movies, I recommend starting with La Montaña Sagrada (The Holy Mountain) and maybe a tab or two of acid- it's really really tripped out shit.