John Cale & Terry Riley, two of the most important names in 20th century composition, formed an unlikely alliance for this one-off project in 1971. The result was one of the weirdest entries in either sonic titan’s personal oeuvre.

First of all: look at that cover art! After dozens of listens, I still don’t know the significance of this, yet have grown more fond each time I see it. The care and attention put into this is a small signifier of the music within; the big picture may seem obviously grand on first glance, yet astounding little details emerge during close inspection and bring the project into focus when one returns to the wider view.

Instead of performing a balancing act between Riley’s spacey minimalism and Cale’s avant-rock nature, each artist seems to pull the other in a direction previously unexplored. Of course, it’s not entirely surprising if you’re familiar with the output of both geniuses, but the sound is defiantly no exact split down the center of their respective sensibilities. From raging textural passages to alien placidity, through jazz whispers and on to a straight up vocal number, there’s more variety in these five tracks than a good portion of the rest of their careers.

The opening features Riley-an organ tones riffing over a krautrock groove of moaning guitars and intricately barbaric drumming, the whole jam subtly erupting and then sighing to a close. Second track The Hall of Mirrors in the Palace at Versailles hews closest to Riley’s minimalist nature with an appropriately meandering, lost-organ and woodwind shuffle while the short closer, The Protege, feels almost like a lost bluesy instrumental from The Velvet Underground‘s golden days (when Cale was in the group). Everything in between veers wildly between these extremes and even, in the epic centerpiece Ides of March, shoots for the moon in a song so neurotically busy with busted drums and ticklish piano that it manages to evoke one of my favorite turns of phrase: maximized minimalism.

The project seems to have been such an exception for each artist that, by all accounts, neither was satisfied with the end result. Luckily for those of us with an outside view, the work stands on its own as a unique hybrid, a historical artifact, and an eclectically bopping good listen.

You can unearth this brilliant jewel of a buried treasure at cduniverse or amazon.