Some discussion of the early history of Western music is necessary in explaining the ancestry and origin of the Swedish nyckelharpa.
In the early Middle Ages, vocal music was performed as a single melody line (monophony). Gregorian chant (or plainchant) originated circa 800-1000 AD, from an older tradition of sacred singing in the early church. This musical style was based on scale arrangements called modes which have a theoretical basis going back to Classical Greece via Jewish and Byzantine religious traditions. Our modern major and minor scales are a weak bi-modal descendent of this system. Modern Western classical music developed in a different direction: that of harmonic modulation.
One of the musical innovations of the Middle Ages was the introduction and development of polyphony, the singing of two musical lines simultaneously. This began as singing in simple octave intervals for mixed choirs of men and boys. Later, melodic lines based on intervals of parallel fifths or fourths developed. This style of singing, called organum, was first described around 895 AD. Organum was not true polyphony, featuring an independent melodic part. It was instead a reinforcement of the main melody, typically sung as the highest line. The first reference to organum describes a well-established practice, so the actual date it became popular is not known. True musical notation only began around 900 AD, so earlier history remains obscure.
The practice of organum singing created a parallel fashion in musical instruments, in which continuous sound either in parallel to the melodic line or as a fixed drone became popular. Pipe instruments (in the form of organs and bagpipes) and stringed instruments were particularly well suited to this style…
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