Documenting the curious world of the hurdy-gurdy.  Tuning and
temperament  Although we’re all familiar with the idea that an A
is defined (since 1939) as 440Hz, many people are less familiar
with how the frequencies of all the other notes are defined. 
Notes an octave higher are, by definition, twice the frequency. 
However, this is where the simple definitions end.  To hear
sweet sounding chords, the frequencies of the notes should be
such that that their component harmonics coincide frequently. 
However, it turns out that by simply choosing equally spaced
frequency differences between every note in the scale, we end up
with out of tune intervals (such as major thirds, minor thirds,
perfect fifths, etc).  This is the best overall compromise that
can be done on an instrument such as the piano, which must play
in any key.  However, this paper by Graham Whyte (presented at
the Over the Water festival in 2002) and hosted by luthier Chris
Allen argues that the fact the gurdy generally only plays in a
few keys all