Stockhausen - Klavierstück V (Audio + Score)

In this piece, melodies and chords are ornamented in different ways in order to provide a surrounding coloration. The "normal" notes (scored with normal-sized note-heads) are referred to as "central tones", and the surrounding "satellite tones" (notated with small note-heads connected to a crossed tie-line) are placed before, after and surrounding the central tones. These "solar systems" of harmony can be considered as individual groups. With the use of pedalling, the harmonic coloration of a group can be manipulated further (beyond the note-based coloration of the grace note satellites). This idea of central tones and satellite tones would, in the future, become very important as one of the "accessory effects" in formula-based compositions such as MANTRA and in the LICHT opera cycle.
Structurally, Piano Piece 5 is in 6 sections, each with its own basic tempo but with many ritards and accelerandos (the initial section starts at tempo 80, moves up to 113 in the middle, most active section, and then drops down to 63.5 as the piece fades out, with a few coda-like groups). The grace notes themselves start out as mostly loud in the first tempo section, then soft in the second tempo, and then a mixture from then on (but organized in different ways). There are also 2 places where a sequence of chords and notes are played with a constantly changing dynamic - kind of like a "loudness row" (I like to think of these as Stockhausen "inserts" - a frequent technique of his, where he breaks from the "main idea" and goes on a "diversion" of sorts, to concentrate on an interesting secondary sound or idea). Various chord groups (and sustained points) are spread throughout, and a "fully notated" note cloud (ie - not grace notes, but very fast) occurs in the middle section as well.
This set of piano works (Pieces V-X), like the first (KLAVIERSTÜCKE I-IV), organizes durations and pitches (rhythms and melodies) in a very different way than the piano pieces of Bartok and Debussy (not to mention Chopin and Schubert!). Building on the chromatic, mathematically-ordered musical explorations of Schoenberg and Webern (as well as his own first set of KLAVIERSTÜCKE), Stockhausen uses serial distribution methods to create unpredictable and irregular rhythms and melodic shapes which have less to do with development of melodic themes and harmonic progressions, and more to do with the movements and patterns found in nature (stars, ocean waves, wind, volcanic eruptions, etc...). The exploration of "point music" (isolated and scattered pitches in space) and "groups of points" continues from his first set of piano pieces, but added to these were new playing techniques, compositional pitch-grouping concepts and notational innovations. As a group of piano pieces, all 6 of these works also use different compositional devices and playing techniques to summon a new spectrum of resonating colors out of the modern piano.
Variable Form
Though the completion of these 6 piano pieces span a time span of almost 7 years, they all use the "indeterminate" idea of allowing a performer's style and natural playing ability to define certain rhythmic shapes and speeds. This was Stockhausen's first steps towards "aleatory" scoring, that is, writing with some musical elements "free" (rhythm and note sequence, usually). Apparently, after having used a ruler to measure out exact (and obviously, determinate) time lengths on magnetic tape for STUDIE II, Stockhausen now took a different, contrasting path (this pattern of constantly switching approaches would continue for the rest of his life) and used the "human timing" of a performer's playing technique to measure out rhythmic durations.
Stockhausen dubbed this kind of performer-based composition as "variable form", and in KLAVIERSTÜCK V, the grace notes (actually strings of grace notes) were to be played "as fast as possible, but articulated clearly (slower in lower registers than in the upper) and not quasi-arpeggiated...." Jonathan Harvey states (somewhat wryly, in "The Music of Stockhausen") that in KLAVIERSTÜCK V, "the grace notes, which exist independently of the tempo, have their own scale of speeds, depending on how awkward they are to play clearly." These works are not quite "aleatory" however, since the durations are still based on the "fastest" speed a performer can play. In later works (starting from 1959 in ZYKLUS), notes would be indicated and then a player could choose and place these notes in any order (and at any point) during a specified time span, making them truly free and aleatory. (Ed Chang)