The constant goal of my searches and efforts: the power of transformation – its operation in time: in music. Hence a refusal of repetition, 
of variation, of development, of contrast. Of all, in fact, that requires ‘shapes’ – themes, motives, objects, to be repeated, varied, 
developed, contrasted; to be dismembered, rearranged, augmented, diminished, displayed in modulation, transposition, inversion 
or retrograde. All this I renounced...

... Never is the same thing heard twice. Yet one has the clear feeling that an immutable and extremely homogenous continuity is never abandoned. 
There is a hidden power of cohesion, a relatedness among the proportions: a structure. Not similar shapes in a changing light. Rather this: 
different shapes in a constant all-permeating light.
          —Karlheinz Stockhausen, 1956, for a radio broadcast of his music

There are few pieces that deserve the appellation “cosmic,” but Klavierstück X is perhaps one of them. Not in the usual hyperbolic sense here,
but quite literally – from formal design to aesthetics (with their undeniable celestial quality), the piece seems to mimic the birth of the universe,
acted out on the piano. An initial cosmic explosion, a kind of primeval “Big Bang” from which all material of the piece’s universe is contained,
gives way to a final apotheosis, with those same building blocks wheeling through space and time. It is a kind of modern myth of Genesis, in music.

Klavierstück X literally translates to “Piano Piece 10,” but the number refers more to its place in an unfinished series of 21 piano pieces rather
than being a chronological designation (#11 was completed before #9 or #10). For a ten-year period between 1951-1961, Stockhausen’s efforts
at the piano were directed at this cycle, completing the first eleven before apparently losing interest in the project. The Klavierstücke were to be
grouped together in sets according to a specific numerical sequence (4 6 1 5 3 2), with #10 originally conceived as the last piece of the second set.

The piece’s aesthetic is grounded in the tradition of the post-war European avantgarde, of which Stockhausen was a major figure. This
generation of composers, growing up in Europe between the wars, came of age in the 1950s to a world in ruins and a musical tradition all too easily
subverted for totalitarian purposes. Their searches to create credible art in this brave new world took them to the serial techniques of Schoenberg
and Webern, and the possibilities of expanding those same techniques to determine all parameters of composition.

In an interview, Stockhausen once declared that, at its heart, serialism was simply a process of mediation between extremes. In Klavierstück X,
those extremes are Order and Chaos, with a gradual progression from Chaos to Order. This prompted Herbert Henck, author of the definitive book-
length analysis of the work, to remind us that “the change from disorder to order is the definition of creation.”

To those interested in further exploration, a website set up by French pianist Florent Boffard, a kind of interactive program notes, cannot be too
recommended – For the uninitiated, Boffard recommends approaching the music as a person discovering
the music of another civilization, or observing a play in a foreign language. Perhaps more apt would be to imagine this the music of an alien civilization.
No doubt Stockhausen, who famously claimed to be from outer space, would have approved.