The Process Plan Works (aka - the "plus-minus pieces")

"Not an accessible entrance."
Group Stockhausen 1968
(Alings, Gehlhaar, Stockhausen, Fritsch, Bojé, Kontarsky - Stedelijik Museum, Amsterdam)
(Score front © Universal Edition)
No. 23: PROZESSION (Procession)
1967 (Duration at least 23')
1967 Instrumentation: tam-tam with microphonist, viola (with contact mic), electronium, piano, sound mixer
1971 Instrumentation: tam-tam with microphonist, electrochord (zither w. synth), electronium, piano, sound mixer

Fred Alings and Rolf Gehlhaar on tam-tam and microphone.
(Score photo © Universal Edition)
     PROZESSION is an important marker for Stockhausen in several ways.  This was the work which began a compositional trend of substituting plus (+) and minus (-) signs for traditional notation, leading to more and more kinds of symbol-based instructions, and ending up finally at text-based "preparatory" instructions for a player's state of mind and nothing else.  Ironically enough, the 1963 work PLUS-MINUS did not actually use "plus-minus notation".

     Another important event here was the crystallization of Stockhausen's live touring band, "Gruppe Stockhausen".  This 6-piece ensemble (including Stockhausen) consisted of veteran KLAVIERSTÜCKE/KONTAKTE pianist Aloys Kontarsky and MIKROPHONIE I collaborators Fred (Alfred) Alings, Harald Bojé, Rolf Gehlhaar and Johannes Fritsch.  MIKROPHONIE I was actually the first gathering of this ensemble, but with PROZESSION the chemistry of these contrasting personalities on their "signature" instruments was first realized.  In fact PROZESSION was written specifically for this unique group (the parts are labelled "Elektronium", "Tam-tam", etc...).  This group (later with Peter Eötvös and others) would reach its ultimate zenith (or nadir, for some) in just a few years with the above-mentioned "intuitive" text compositions AUS DEN SIEBEN TAGEN and FÜR KOMMENDE ZEITEN.

     In his quest to explore new sound worlds and new structures, Stockhausen wasn't interested in doing variations on the works of his contemporaries.  However, drawing on excerpts of his own past work was apparently acceptable (and even had a precedent in MIKROPHONIE II where "time-windows" would open to expose taped excerpts from GESANG DER JÜNGLINGE, CARRÉ and MOMENTE).  In PROZESSION, many of the works mentioned above would be designated as "sound pools" from which the group could draw from and manipulate.
Harald Bojé on electronium, a kind of accordian-synthesizer (not the Raymond Scott device).
Bottom Left - amplifier.  /  Bottom Right - reverb amplifier, volume pedal.
(Score photo © Universal Edition)

     The score is printed as 4 individual parts, 2 pages for each instrument (piano, tam-tam (gong), viola with contact mic and electronium (or el. organ/synthesizer)).  The parts are written as symbolic instructions for creating 250 "events", but the initial event must be a transformed "quote" from one of Stockhausen's previous works.  Each instrument has it's own repertoire to draw from:
Tam-Tam & Microphonist MIKROPHONIE I
     Since the events are born from these earlier Stockhausen works, it may be somewhat interesting to hear these works first before listening to PROZESSION (but is definitely not required). KLAVIERSTÜCK XI is a meticulously varied piano work of different attacks and durations. KONTAKTE is an electronic work usually accompanied by piano and percussion, with the intent to make "contact" between the synthetic and acoustic timbres.  MIKROPHONIE I is concerned with creating a large palette of tam-tam (gong) timbres through the use of unconventional tools to scrape , bow and strike the metal surface. GESANG DER JÜNGLINGE is Stockhausen's electronic work merging synthetic tones with a boy soprano's singing voice.  MOMENTE is a large work for voice, brass, percussion and organ which, among other things, explores connections between vocal soloists and percussion. TELEMUSIK is an electronic work which mixes transformed field recordings of global folk songs with electronic music, and SOLO is a work utilizing tape delay, but also includes 6 pages of notated material consisting mostly of quiet long tones or brief fast passages, with different kinds of pitch bending and vibrato techniques.

    Each player can start at any time.  "Plus-Minus" notation (below) indicates that the event must be more, less than or the same as the previous event (or the original Stockhausen work in the case of the first event) in one of 4 musical parameters:
+ Higher register / Louder dynamic / Longer duration / More segmented rhythm
- Lower / Quieter / Shorter Less segmented
Same (or similar) register / dynamics / duration / timbre / No. of segments
Longer or shorter duration refers to the length of an event.  Changing the "segmentation" is basically changing the number of notes in a phrase without changing the melodic shape, typically by dividing long tones into several shorter ones or playing tremolos. 

(Combined score of Tamtam, viola, electronium and piano. © Universal Edition)
     Each symbol is applied to one parameter.  When there are multiple (stacked) symbols, they are applied to different parameters.  A "+" and a "-" stacked in the same event could even be applied simultaneously to the same parameter by alternating or otherwise mixing the two values.  All symbols can be reassigned to different parameters for each event unless the score indicates "IM GLEICHEN PARAMETER", which means that successive signs are to be applied to the same parameter during the bracketed sequence (excluding the symbols above and below the bracket).  Any parameters which have not been chosen for transformation remain the same.
     So, if a player has 2 symbols and chooses register and duration as the parameters for change in the next event, dynamic and segmentation remain the same (unless one of the 2 symbols is an "=", in which case register or duration stay the same as well).

     A player can also choose to drop his own event and imitate another person's current event (with the plus-minus modification(s) applied).  Basically, after finishing an event, the player can:
  1. immediately go on to his next event
  2. pause, and then go on to his next event
  3. pause and listen to another player's event, and then at any time "jump in" to that person's event (after the event has finished)
     Timbre is not a symbol-controlled parameter (and so can be varied from event to event), but when jumping onto another person's event, the timbre must be the same (or an approximation). Droning seems to be encouraged since Stockhausen asks that each player must play a VERY long event (> 1 min.) at least once during a performance (this long event should be during a "+" event, followed by a shorter "-" event). When "Per." is indicated, the rhythm must be periodic (evenly pulsed).

     At certain points a "leader" instrument is indicated by a box with letters and numbers (sometimes with "GIBT").  At these points the player (or "GIBT"-indicated leader) makes a signal and the other instruments must match the leader in register (R), volume (İ, for intensity), duration (D), and/or rhythm (G, for glieder (German, "limbs")).   The number after the letter symbol is the number of events in which they must follow the leader.  In the electronium score page above, [R D 8] at the beginning of the second line indicates that the electronium signals and leads in register and duration for 8 events.  In the scores for the other 3 instruments that event is labelled with "ELEKTRONIUM GIBT" ("electronium leads").

     The sequence of leaders is listed in the table below and it may be possible to follow a performance with this scheme (but good luck!).  In the timing column are my "guess-timates" for the 1971 performance on Stockhausen Edition CD 11.
Sync Timing Leader Parameters
3 20:57 TAM-TAM VOLUME (7)
5 27:05 TAM-TAM DURATION (11) and RHYTHM (5)
7 31:18 VIOLA
8 33:15 PIANO DURATION (6) and RHYTHM (3)

     Finally, if a beginning (or ending) sounds similar to one from a previous performance, then the performance must begin again (or continue, in the case of a similar ending).

     The score doesn't specifically mention whether each event must derive from a different Stockhausen work passage, or if a single excerpt only is modified on successive events.  It only says "Every event must be a variation of an event taken from my earlier compositions".  Based on listening to recordings, it seems to be a little bit of both.  In general, an event goes through a few additive-subtractive variations, and then a new event from the "Stockhausen work pool" takes over.

     The score mentions at the very end that other "corresponding instruments" can also be used to play the work (instead of electronium, tam-tam, viola, piano) and other Stockhausen works may be used as event sources.

     There are some interesting trends which result from Stockhausen's Plus-Minus sequences.  In each player's part, almost 1 out of 4 events is marked "periodic", and when layered on top of each other, a periodic event of some kind is probably occurring during most of the entire performance.   Also the recorded performances tend towards long periods of static textures alternating with explosions of activity which are initiated by one person and then imitated by the others.  These climactic louder sections are usually based on periodic rhythms or tremolo-oriented.

The title PROZESSION is ambiguous: on the one hand it indicates that I have not composed a
"piece" like a fixed object, but rather a "process" in which musical events are transformed; on the
other hand it suggests a procession, such as one experiences in religious festivals, when everyone
marches, singing and praying through the streets or the countryside, and each song or prayer that is
struck up in the first row of the whole procession (or of a large group within it), makes its way
towards the rear, row by row, until it has reached the very last straggler.
(Stockhausen, Kürten, 6/2/1975)

     One question that may come to mind is: why is timbre not one of the four parameters?  This is probably because it would be difficult to interpret timbre as degrees of extremes ("more timbral?").  In any case, timbre was already used as a structural element in the work SOLO, which asks for 4 unique timbres.

Stockhausen controlling the "filters and potentiometers" using
a Maihak W49 bandwidth filter and a multi-channel mixer.
     PROZESSION was first conceived and performed on tour in 1967 and premiered in Helsinki, Finland.  This particular line up of the group (listed earlier) recorded and released 2 performances.  In 1971 a new line up (featuring Harold Bojé (electronium), Christoph Caskel/Joachim Krist (tam-tam), Peter Eötvös (electrochord & synth), Aloys Kontarsky (piano) and Stockhausen (sound mix)) recorded the version currently available on Stockhausen Edition CD 11.

      The 1967 version has a fairly static sound field, whereas in 1971 Stockhausen is much more bold in the spatial panning of the instruments, and the mix is more "up-front".  The substitution of Eötvös' bow-and-zither-driven electrochord synthesizer for Fritsch's viola makes this version a bit more "alien-sounding" than the earlier recording. On the other hand, the 1971 version, besides being markedly shorter than the 1967 version (35 vs. 49 minutes), also seems to deviate from the score at times for the sake of organic development and interaction.  I might advise hearing the 1967 version first to get used to the sounds and types of transformations, but the 1971 version is a bit more enjoyable for fans of really "out-there" music (though the 1967 version is plenty "out").

Sound Impressions
     The instrumentation of PROZESSION overshadows the composition.  Saying that may seem to diminish the importance of Stockhausen's exploration of "plus-minus" transformative notation, but in my opinion the sounds of the electronium, electrochord and tam-tam are so alien and timbrally complex ("noisy") that for me, they really tend to define any recordings featuring them.  In fact, it would be very difficult, if not impossible, for me to distinguish in a blindfold test whether this group were performing PROZESSION or one of Stockhausen's intuitive text pieces from AUS DEN SIEBEN TAGEN (or at least some portion of it).

      I think however that this work is important in that it's development was a necessary step (along with the soon-to-come shortwave radio-accompanied pieces) towards total intuitive music.  The ideas behind event-driven transformation first explored here are the backbone behind all of Stockhausen's many later works with this ensemble, and as mentioned at top, the unique "sound" of Gruppe Stockhausen was first established with PROZESSION.  They would go on to explore additional species of Plus-Minus process works in KURZWELLEN, SPIRAL, POLE and EXPO.  In a way, these works would "train" Stockhausen and his crew of sound-explorers to structure and control their journeys and avoid emulating the typical "slow build - climax - release" dynamic envelope of most other free (jazz) improvisation ensembles of that time.

Rolf Gehlhaar's Memoir on performing PROZESSION
PROZESSION Sound samples, tracks listings and CD ordering 
Buy the Score
Sonoloco Review of PROZESSION
Youtube clip of PROZESSION 1967
Youtube clip of PROZESSION 1971 
PROZESSION (ensemble recherche + Experimentalstudio SWR Freiburg) 2009 in Poland at the Musica Electronica Viva festival (live clip)
On Harald Bojé's Electronium
On Peter Eötvös' Electrochord
Electronium at 120 Years of Electronic Music