Organ clock music encompasses only a very small segment of our Western musical culture. Despite the fact such an area of music does exist in its own right. On the one hand, a composer who is writing for a small organ clock is limited by the range and volume of the instrument, but on the other hand be has completely different tone qualities as his disposal. The limits and possibilities of manual playing techniques do not play a role here at all. Even 15-part chords or simultaneously played chords with runs or trills are possible.
Examples can be found at Mr. Naeschke site.
With the pinned barrels of these small organ mechanisms the most subtle variations in tempo and rhythm are possible. By influencing the response of the pipes, the finest nuances in articulation are obtainable, since the valves can be opened a various speed. In short, music be made more lively than is possible when a musician himself plays.
The designer who marks the barrel must be a sensitive musician who has experience in harmonization and ornamentation and finds an ideal form of musical expression in his making of the barrel. The barrel itself has had a long tradition lasting over 500 years, having been used for chimes, mechanical spinets, harp clocks, then organ clocks, as well as for ordinary barrel organs. From the middle of the eighteenth century onwards, the heyday of the organ clock, the possibilities for rendering music with the pinned barrel reached a state of perfection. Essential for such perfection, however, was the precision and durability of the organ clock movements achieved by the clock makers of the time.
An important factor which can be put to good musical effect is the perfect harmonic tuning possible with this instrument only. For diatonic organ clocks with an additional F sharp this means: the major thirds G – B, C – E; D – F sharp; F – A and the 6 fifths F – C; G – D; A – E; H – R sharp; C – G; E – B are beat-free. For chromatic organ clocks the notes C sharp, E flat, G sharp and B flat are tuned as beat-free major thirds. (Middle-tone tuning would also be possible). In this way not only do beat-free thirds and fifths result, but also beat-free fourths, beat-free whole tones, beat-free tritons. The musical result is that one produces a perfect fusion of intervals and chords, thus producing the corresponding lower combination tones.
These combination tones give the small instruments a much greater acoustic capacity. The impartial listener expects the pipes to be lager. In organ clock compositions, individual, separately composed chords are heard as single tones with varying tonal colour, similar to the tone quality of the cornet tone of a large organ, which , after all, consists of 5 pipes. However, the acoustic effects can for the most part be achieved only within the range which is normal for organ clocks. When the instrument is played at considerably higher or lower pitch levels these effects are lost.
The highest note of a 1-stop organ clock is somewhere between g 3 and c 4 , i.e. at about 2000 hertz. Likewise, one only finds notes below g 0 in instruments with several stops. Even in earlier times they no longer played any authentic organ clock music. A primer for achieving musical effects on the organ clock acoustically and by means of playing techniques are J. Haydn’s small and large pieces for organ clock . In especially fast arpeggios or runs what results is a kind of harmonic murmuring, such as in the Presto No. 3 in measure 12 – 13 and 32 – 33, where the intervals as such are not recognizable. In the Presto No. 12, bar 32 and in similar passages one is also not aware of what is really going on. These small pieces for organ clock play for 28 seconds, with rhythmic accentuation of the downbeat only.
Table organ clocks are produced in different design. Bevelled glass panels at the sides are possible, also visible tin pipes in the case front. In bracket clock style the organ clock has 17 pipes and a organ movement with barrel and fusee.
A masterpiece among Haydn’s organ clock music is the Allegretto No. 27, which was originally found on the barrel of an organ clock presented to Prince N. Esterhazy in 1793 and published one year later, in 1894, as a piece for harpsichord or pianoforte. The organ clock plays this piece in 40 seconds. To be useful as a piano piece it should be played at about half that tempo, yet the effects which are only possible when it is played on an organ clock are lost. Rhythmically speaking, the piece clearly heads towards a first climax, the G-major chord in the second bar. Due to the correct harmonic makeup, the chord is experienced by the listener as s single tone, accompanied by the lower combination tone, especially since it has been preceded by various tone colours, in part with a doubling of the third, which enhance this effect. Similar effects are to be found in several parts of this piece. In the seventh bar the individual notes are not perceptible, but once more they produce merely a kind of structured murmuring. In bars 16, 17 and 18 the various chords sound like single tones with peculiarly differing tone colours. They do not sound at all wrong or out of tune as would be the case with the piano! Bars 21 and 22 really come to sparkle with their harmonically correct composition. Typical for the sound of the organ clock are also the sixteenth-runs starting in bar 8, the low whole-tone trills, the triplets from bar 29 on and the thirty-second-runs and movements from bar 30 onwards.
This is music which one can and must listen to time and again. Every time it is a new challenge to explore the musical subtleties of it in depth. The music is purely instrumental. When other pieces of music are arranged for the organ clock, these criteria have to be taken into account.