Short octave

(Fr. octave courte; Ger. kurze Oktave).

A term to denote the tuning of some of the lowest notes of keyboard instruments to pitches below their apparent ones. The practice was employed from the 16th century to the early 19th to extend the keyboard compass downwards without increasing the overall dimensions of the instrument.

The short octave was not described in theoretical writings before the 1550s; the alleged description of it in Ramos's Musica practica (1482) results from a misinterpretation. However, the system originated earlier in stringed keyboard instruments. It was basically a variable tuning adapted to the requirements of individual pieces, comparable to the Scordatura of string instruments. It was first applied to keyboards showing F as the lowest key; the F and G keys, if present, were tuned to sound lower notes, usually C, D or E. By the middle of the 16th century an apparent E was added as the lowest key, but it was often tuned to a lower pitch. This soon resulted in the standard tuning known today as the ‘C/E short octave’ (fig.1), but keyboard music sometimes called for other tunings, including some chromatic notes. The system was applied to the organ only at the end of the 16th century, since retunings were impractical and the pedal often provided the required low notes. At the beginning of the 17th century some composers applied scordatura to the chromatic keyboard beginning with C, the C key being retuned to A'. This led to the standard ‘G'/B'short octave’ shown in fig.2.

The short octave developed because the bass part of the keyboard repertory was usually diatonic. It may have been conceived at first as a means of allowing to play on the manual keyboard of string instruments what, on the organ, would have been played on the pedal-board. Several early keyboards show traces of pedal pull-downs under the short octave keys. The short octave arrangement has also been used for diatonic pedal keyboards, perhaps because it made the identification of the keys easier than in a single row of identical keys. From the 17th century onwards, however, composers often demanded a chromatic compass in the bass and so manual keyboards were enlarged, a process known as Ravalement (literally ‘enlargement towards the bass’); or else the two lowest upper keys were split into two parts, the front tuned to the short octave note, and the back to its proper note, a system known as Broken octave (i).

BIBLIOGRAPHY

G. Kinsky: ‘Kurze Oktaven auf besaiteten Tasteninstrumenten’, ZMw, ii (1919–20), 65

N. Meeùs: La naissance de l'octave courte et ses différentes formes au 16e siècle (diss., U. of Leuven, 1971)

N. Meeùs: ‘Bartolomeo Ramos de Pareja et la tessiture des instruments à clavier entre 1450 et 1550’, Revue des archéologues et historiens d'art de Louvain, v (1972), 148–72

NICOLAS MEEÙS