Arnold Schönberg‘s, Drei Klavierstücke, op. 11-I (1909) played by cats on pianos,
by Cory Arcangel (2009).

Schönberg’s Op. 11 is often considered the first piece of “atonal” music, or music to completely break from traditional western harmony which means it’s not written in a “key”. 

II

III

More info on http://www.beigerecords.com/cory/Things_I_Made/DreiKlavierstucke.

Related:

Marija Djordjevic Céleste Boursier-Mougenot Maurice Methot Samir Mougas