This month, as part of the Sunday Specials, Fine Music 102.5 begins a series of monthly programs dedicated to the 24 diatonic keys. Titled Master Key, it begins with C Major on the 18th of September.
The system of keys developed from the Church modes that were used to sing the liturgical chants of the middle ages. The modes originated in Ancient Greek musical theory and while they have many features common to the major and minor scales of later Western Music, they have many differences. For instance, most do not have a leading note (Major 7th above the first note).
The first harmonies notated in Western music history are known as organum—a practice of singing plainchant in parallel fourths or fifths. While organum created polyphonic music, the practice did not function in the same was as harmony. As polyphonic music evolved, performers, and eventually composers, altered the notes of the modes to invent the cadences and progressions that we might recognise today as functional harmony. Over time these alterations to the modes became codi ed and the system of major and minor scales and chords was established.
At the same time, systems of tuning were evolving to provide the exibility for major and minor keys on all twelve notes to sound good. There were many different tuning systems that divided the octave by slightly different methods. The most important were Pythagorean tuning and Just Intonation. Explaining the differences between tuning systems can be very complicated and technical, but the thing to remember is that these systems did not divide the octave into twelve equal semitones. This meant that some keys sounded much as modern listeners would expect, but others had tuning anomalies that made them sound very uneven. Equal temperament is, therefore, a compromise tuning system in which the octave is divided into twelve equal semitones.
Equal temperament had been theorised by several people during the Renaissance Period, including Vincenzo Gallilei (father of Gallileo Gallelei), who composed dance suites on all 12 chromatic notes and in 1568 included ricercares in all keys in his instructional book for the Lute. During the baroque period equal temperament became desirable as theories of triadic harmony, such as that developed by Rameau, suggested the possibility of tonal modulation to distant keys within a single work. Such modulations were limited only by the extent to which the tuning system would allow the harmony to sound well in distant keys. Bach’s masterpiece of the Baroque, the Well-Tempered Clavier, explored the 12 major and 12 minor keys not once but twice. It is debatable whether ‘Well-Tempered’ means ‘Equal Tempered’, however we would assume that the system of temperament used by Bach would have been very close to equal.
Many instruments of the baroque period were not well suited to playing in all twelve major and twelve minor keys as lute or keyboard. So Telemann’s comprehensive set of Fantasies for solo flute only includes twelve different keys. Absent from the set of Fantasies are the keys that are very difficult to play on Baroque flute, such as B major and C minor. It was only in the late 19th century that all the woodwind instruments had been developed to the stage where playing in all keys with equal technical proficiency was feasible. Until the invention of valves in the mid-19th century, brass instruments (other than the trombone) needed either a system of crooks to change the length of the instrument (horn) or a set of different sized instruments (trumpet) to play in different keys, limiting these instruments and symphonic music to a much smaller set of keys.
Since the time of Bach, many composers have composed piano works in all keys, including Shostakovich, Chopin and Rachmaninov. Other composers have been fascinated by particular keys, such as Beethoven, who is associated with E flat Major, the key of his Eroica Symphony and Emperor Concerto.
The Master Key series begins on Sunday 18 September at 3pm with C Major. Highlights include the C Major Prelude and Fugue from the Well-Tempered Keyboard by J.S. Bach and Bizet’s wonderful Symphony in C Major. Sadly a two-hour program is barely long enough to cover the many gems composed in each key. We are keen to hear your favourite works in particular keys. Please tune in to hear our Master Key Series on the third Sunday of the month, beginning in September.
– James Nightingale