"Concert for Piano and Orchestra" and "Atlas Eclipticalis" by John Cage are among the most important and influential pieces of the 20th century music. They represent a culmination of Cage's revolutionary concept of time, sound and form, which so influenced the music in Europe and America in the 50s and 60s. Both orchestral pieces are not based on the traditional score.

The S.E.M. Ensemble, with pianist Joseph Kubera and conductor Petr Kotik, had worked closely with Cage for more than two decades. Both pieces are recorded in full versions, including all 86 parts orchestra in "Atlas Eclipticalis". The recording was supervised by the composer.

Eric Salzman wrote in an article to these works: "This music is a walk down an unknown city street or perhaps a forest or a meadow where birds may sing and trees may fall and mushrooms grow."