A system of letter notation seems to have grown up contemporaneously with the neumatic system. Its invention has been ascribed to Gregory the Great and to Boethius, without much authority in either case. The first instances of its practical use are found in the writings of Notker Balbulus and Hucbald. Originally fifteen letters were used to designate the tones of two octaves; this number was afterward reduced to seven, repeated in successive octaves. The letters ran from A to G, but none of them had a definite tone meaning, as they have with us. A was merely the tone taken as a starting point and the series was always counted upward from it. In the system as it was finally completed the lowest G was added and called gamma to distinguish it from the G in the regular series. It is of interest to note here that the introduction of B flat necessitated the use of two differently shaped B’s. The B durum was angular
and the B molle was rounded
. From the former was derived our natural sign (♮) and from the latter our flat sign (♭). Our sharp is merely a variation of the natural. The system of letter notation was originally devised chiefly for instruments, particularly the organ, though its use gradually became universal. It belongs, however, more properly to a period later than the one we have been discussing.
One other item may justly find a place in this chapter, namely, the early history of the organ. The instrument has virtually since the beginning of our era been associated with the church, and was already a factor in the service during the plain-song period. We shall presently see how one of the earliest forms of polyphony—of music that was not merely plain chant—received its name from the instrument. The organ is of ancient origin; according to Riemann, its ancestors are the bagpipe and the Pan’s pipe. Already in the second century B. C. there existed a true organ, in which air pressure was generated by pumps (bellows) and compressed by means of water pressure and the manipulation of a keyboard. The invention of this so-called water-organ (organum hydraulicum, hydraulic organ) was ascribed to Ktesibios (170 B. C.) by his pupil Heron of Alexandria, whose writings have come down to us. Water was, it seems, not a necessary accessory to this instrument and organs were soon after constructed without the hydraulic principle, in Greece and Italy.
The Organ in the Middle Ages.
1. Pneumatic organ, 4th century.
2. The famous Winchester organ, 951, A. D.
3. German organ, 11th century.