1915] on The Piano-Player — Scientific Aspects 401 



regulating bellows by means of a lever carrying a sliding weight, the 

 usual spring being removed. The sUding weight acted originally on 

 the principle of the common steelyard, thus enabling the tension on 

 the bellows to be varied from time to time in playing different 

 passages. It is convenient to describe such changes as " sub- 

 permanent." Further, the lever itself could be controlled by hand, 

 and could have upward or downward pressures instantaneously applied 

 to it for the purposes of accentuating individual notes, such changes 

 being describable as " temporary." The usual expressson marks FF, 

 F, MF, P, and PP, were placed against the different positions of the 

 sliding weight in order to enable a beginner to obtain increased 

 range of contrast by following the indications on his music. 

 The experiments lead to the following conclusions : — 



1. By varying the sub-permanent tension independently of the 

 pedalling, differences of effect are obtainable that cannot be produced 

 by the ordinary methods of control. A light sub-permanent tension 

 with fairly strong pedalling will give bright treble effects Avith light 

 bass. A heavy sub-permanent tension with light pedalling produces 

 a strong bass and a soft treble. These effects are undoubtedly due 

 to the closing of the regulating bellows being accelerated in the one 

 case and retarded in the other, thus varying the duration of the 

 maximum tension and the character of the striking action. 



2. Corresponding to every note of the scale, there is a position 

 of the sliding weight which produces the maximum effect, this 

 position varying continuously from one end of the scale to the other. 

 The theoretical explanation of this experimental result may be that 

 we have to deal with two systems which closely resemble each other, 

 one consisting of the regulating bellows and loaded lever, the other 

 of the playing pneumatic and pianoforte hammer. The maximum 

 effect naturally occurs when their motions synchronize. 



3. The brightest effects are obtained by keeping the accent valve 

 open or partly so, as in this case the closing of the regulating bellows 

 is affected by the pedalling. The effect of closing the accent valve 

 is very similar to the use of the soft pedal. It is, however, some- 

 times necessary to use this valve for accent effects which are other- 

 wise difficult to produce — i.e. bringing out single notes from the 

 midst of a heavy accompaniment. In any case the spring of the 

 accent lever is best removed so that it will rest in any position. 

 Even in these cases the expression device greatly improves the 

 accentuation, as there is far less risk of the regulating bellows 

 rebounding and crashing out notes following the accented one. 



4. In playing solo passages, light and heavy sub-permanent ten- 

 sions produce different effects even when it is sought to maintain 

 the corresponding degree of loudness by suitable variations in the 

 strength and method of pedalUng. This observation led me to 

 believe in the existence of a relation between tone-quaUty and touch, 

 which has since become the subject of a lively controversy. The 



