Karlheinz Stockhausen
HIMMELS-TÜR
Notes on Performance by Stuart Gerber

The score to Himmels-Tür is, in many ways, relatively straightforward and somewhat "traditional" as compared to previous works by Karlheinz Stockhausen (i.e. no aleatoric elements that need prior organization as in Zyklus, no use of amplification or electronics as in Nasenflügeltanz, and no aspect of instrumentation or notation left to the performer’s discretion as in Komet). The piece is to be performed without amplification, on a prescribed group of instruments (all of which, aside from the door itself, are traditional and easily acquired), with a score that, although written in a graphic style, is easily interpreted by percussionists in the 21^st century. However, after over 30 hours of rehearsals together with Stockhausen working out the technical demands of the score and making corrections and changes where necessary (not to mention the hundreds of hours practicing the work on my own) there are some issues regarding performance practice that might not be readily apparent. I have included some of these below for the interested percussionist who chooses to tackle the difficult, yet extremely rewarding, experience of learning Himmels-Tür.

• Rhythm: Although Himmels-Tür is written using graphic notation (i.e. nontraditional musical notation) the percussionist must take care to heed both the tempo markings and the exact rhythm notated in the score. I found it helpful at the beginning stages of learning the work to notate some of the more dense sections into traditional rhythmic note values. This technique was also helpful during more sparse sections as well in order to keep the correct timing between attacks, especially those that had long periods of time between them.

• Vor/Nachschläge (grace notes): Although these should be approached in the traditional manner (i.e. with the larger note being the primary beat), it is imperative that both notes be clearly heard. To achieve this one needs to be careful not to put the grace note (occurring before or after the main note) too close to the primary note. The main note will be slightly louder simply by the nature of these figures, therefore if the grace note is placed too close to the main note, the main note will cover it dynamically. This is especially true of the Nachschläge or "after beats." At many points in the score I execute an after beat figure by utilizing a controlled double bounce stroke (i.e. one arm motion producing two notes through a bouncing of the mallet). This is useful in producing a slightly softer second note, however the second note must be clearly heard.

• Glissandi: Glissandi figures appear beginning on the fourth page of the score. The performer should take care to make these glissandi the correct dynamic, length, and where possible, pitch prescribed. To do this, one must provide the same amount of pressure to the beater during the execution of the glissandi. The natural tendency when performing these gestures will be to strike the note at the beginning of the glissando, followed immediately by rubbing the head of the beater along the panel in the prescribed shape. This is correct in principle, but this alone will result in a decrescendo so that the glissando is a softer dynamic than the initial note. This should be avoided (unless there is a decrescendo written). In order to achieve a more equal dynamic between the beginning of the gesture and its continuation (i.e. glissando) the performer must apply continued pressure to the mallet throughout the entire gesture. Changing the angle of the head of the beater can help. For example, the normal angle of the beater when striking the door is c. 30-40 degrees. Angling the mallet to as close to 90 degrees to the door as possible when executing the glissandi allows for more pressure to be applied during the glissando. This is especially applicable to glissandi mf or louder.

• Trills: The short trills (a single note head marked with "tr" above it) need not always be performed the same way. They may be performed either using multiple bounce strokes (i.e. a short buzz roll) or a very short single stroke (hand to hand) roll (i.e. 5 or 6 very fast strokes) depending on the context. In general, I utilize a bounced stroke when the dynamic is medium to soft. To execute this I play both hands almost simultaneously (one an instant before the other) while letting the sticks bounce very quickly, kind of like a "press" roll. When the dynamic is mezzo forte and above I usually use a very short single stroke roll as described above. This is of course open to interpretation. Suffice it to say that the performer should explore both options and implement the appropriate technique where applicable.

• Tremolos: I interpret the tremolos in the same fashion as the trills explained above, with both single stroke and bounced strokes depending on the situation. I also utilize one other technique for the long fermata on page 7, second system, 11^th pulse. Here, the score requires that the performer make a continuous tremolo beginning on the lowest panel of the door, moving in a semi-circle along the wooden floor in front of the door, and moving back to the lowest panel of the door on the opposite side. In doing this long tremolo it is important to vary the sound so there is some direction in the gesture. I therefore begin with a single stroke roll but vary the angle and speed of the mallets in order to accentuate different various timbres and pitches of the wooden floor. In the middle of the tremolo I also utilize a stroke in which I use the head AND the butt end of the mallets simultaneously. This creates a very fast and dense roll with both high and low pitches coming from the two sides of two different beaters. This is the only point in the piece that I use this technique.

• Clearly the piece must be memorized (at least the first 16 pages). I suggest making a click track for each individual page for rehearsal purposes to aid in the memorization of the piece. This will also help in obtaining accurate and consistent rhythm.

Equipment

• Mallets: The score calls for large wooden beaters to be used in performance of the piece. I therefore experimented with a number of different types of mallets from the beginning. I tried wooden potato mashers, sculptor’s mallets, wooden bass drum and timpani mallets, and even rawhide chime hammers. However, it became apparent that the mallets with a bulbous head, tend not to have the capacity to bounce on the wooden surface in order to produce the tremolo and trills that require multiple bounces between the sticks. Per Stockhausen’s request I also experimented with leather-covered dowels used to play large Japanese keisu. The attack produced by the leather was, of course, softer than the wooden mallets I had tried. This type of mallet works for single strokes, but unfortunately any type of covering on the wood (leather, chamois, sand paper, etc) does not produce the desired sound for the various glissandi figures found throughout the piece. However, the dowel shape does allow for the production of the buzz-type rolls on the door and produces the desired sound for the glissandi. Therefore I decided to use various kinds of large, uncovered wooden dowels as mallets for Himmels-Tür.

I employed a woodworker to turn various types of wooden dowels on a lathe to make the appropriate mallets. I ended up using different hard woods of varying densities to help contrast the attack, and timbre of panels on the door. I utilized mallets made of poplar, beech, walnut, cherry, and basswood. I had these various dowels turned to produce a tapered shape. The mallets are 17 inches long, and are 1.75 inches in diameter at the beater end, but taper to 1 inch at the handle. The mallets are tapered so that they have a striking diameter large enough to produce a full and resonant sound on the boards of the door, yet have handles thin enough to allow for technical playing required in the piece. I found the faster passages and the tremolos were very difficult to execute when the dowels weren’t tapered. The mallets can be turned around as well so that the handles are used to strike the door at various times where a lighter sound (accentuated higher partials) may be desired, thus encouraging further timbral variation. In addition, I also utilized oak and pine mallets (measuring 15 x 1.5 inches tapering to 1 inch and 14.5 x 2.5 inches tapering to 1.75 inches respectively) that are pre-turned, manufactured table legs I acquired from a hardware store. I often use two different beaters simultaneously to avoid always having the same timbre, to keep variety in the sounds produced.

For the last six pages of the score, where the score calls for cymbals, hi-hats, and tam-tams (pp.17–22), I use a heavy medium vibraphone mallet (Vic Firth M31 model) for the cymbals, and a large, medium hard, yarn wound tam-tam beater for the tam-tams.

Below are the mallets I use for each page:

p. 1 Left Hand pine/Right Hand beech
p. 2 (same)
p. 3 beginning same, last system change to LH oak/RH beech
p. 4 LH oak/RH beech
p. 5 (same)
p. 6 LH walnut/RH cherry
p. 7 (same)
p. 8 (same)
p. 9 LH poplar/RH basswood
p. 10 beginning same, 5^th system beat four LH walnut/RH cherry
p. 11 LH walnut/RH cherry
p. 12 (same)
p. 13 (same)
p. 14 (same)
p. 15 LH poplar/RH bass
p. 16 (same)
p. 17 LH large tam tam beater/ RH med. vibraphone mallet
p. 18 (same)
p. 19 (same)
p. 20 (same)
p. 21 (same)
p. 22 (same)

• Shoes: In addition, the performer is to utilize shoes with a hard, nailed sole to perform the "Schuhe" strokes. In addition to the stomping, the performer must also, from time to time, perform glissandi (sliding the foot along the floor) with the shoes as well. To help bring these gestures out I glued medium grade sand paper to the soles of the shoes so these moments were more present.