Thinking about comfortable octave playing a span of about 8.5 inches (21.6 cm) is desirable in order to:
- eliminate tension in fast, extended octave passages (such as in Chopin’s Butterfly Etude or Heroic Polonaise). This assessment is based on personal experience of a number of pianists who have experienced ESPKs of different sizes and the work of Yoshimura and Chesky (2009) in particular. Tension in octave playing not only results in discomfort but limits speed and tone control, but has been found to increase the risk of injury. (See: Hand size as a risk factor).
- be able to play legato octaves (using 3rd and 4th fingers) as desired.
- minimise inward and outward movement when moving rapidly between black and white keys (such as in polonaises with dotted rhythms). Power is also reduced when the hand needs to come forward and flatten out to play white key octaves rather than being able to reach comfortably over the black keys.
- play ‘cross-over’ octaves – where the right hand crosses over into the bass or the left hand crosses over into the treble without physical awkwardness and discomfort resulting in reduced tonal and rhythmic control as well as accuracy.
- shape the melody line of phrases (e.g. Brahms Intermezzi, Chopin Prelude no. 17) where the thumb is holding down the lower note of octaves and ninths.
Boyle (2013) has supported a definition of a ‘small hand’ (in relation to playing the conventional keyboard) to be consistent with Farias et al. (2002) who defined a ‘small hand’ as one that could not reach a tenth. While the ability to play a 10th is desirable, this benchmark also marks the ability to play octaves with ease, speed and comfort in all situations as described above. It is assumed that a classical pianist may wish to be able to play across a wide range of repertoire, to the best of their ability, including works from the time of Beethoven and Schubert onward.
A ‘small hand’ is defined as one with a thumb to fifth finger span of less than 8.5 inches (21.6 cm) and/or a second to fifth finger span of less than 6 inches (16.2 cm). This is based on the importance of comfortable and tension-free octave playing, the desirability to be able to just play a tenth, the need to be able to play comfortable sixths (and just play sevenths) using the second and fifth fingers, other evidence relating to studies of pain and injury, performance quality and biomechanics plus the experiences of pianists trying keyboards of different sizes (see Pianist Feedback and also trials by Steinbuhler on different keyboards – refer to the shaded keyboard ‘zones’ in his chart showing hand span data – www.steinbuhler.com/html/our_research.html – and also shown here: Earlier hand span studies