Starting from an early Art Tatum influence, but already with much more ambitious 'sliding' tempi, Nancarrow went on to develop an interest in the canon structures of J.S. Bach, taking them to the nth degree and far beyond the limits of human playability. If you're interested in more detail on the theoretical side of this style of composition, the YouTube video below explains it beautifully - and/or you can just go ahead and download these four volumes of Nancarrow's music that he supervised in 1977 and released one at a time in the next few years after.
The sequencing of each album is wonderfully effective - Volume 1 kicks off with one of the most accessible Studies, No. 3, aka the Boogie-Woogie Suite. The sheer joy and exhilaration in this 15-minute stretch of Nancarrow's music alone was enough to get me hooked - and three hours worth, of wildly varying complexity, harmony, and breathtaking rhythm/tempo, is just sheer bliss. Unreservedly recommended.
Disc 1 mega / Disc 1 zippy
Disc 2 mega / Disc 2 zippy
Disc 3 mega / Disc 3 zippy
Disc 4 mega / Disc 4 zippy