Why are some frequencies considered musical notes and some are not?

Question

Is there some inherent quality in the frequencies that make them notes, or is it just an arbitrary human construct?

In: Other

Answer 1

It is a completely arbitrary human construct. In the western world, we have agreed that a note resonating at 440 hertz is a “middle A” (A4), and that the chords and scales we use are built on a logarithmic scale based on that note, 12 notes to an octave scale in “equal temperament.”

There are also 12-note scales built on unequal temperament, whose frequency values deviate from a pure logarithmic standpoint – but they are not widely used today. They *were* widely used in the past, especially in the pre-baroque period.

Non-western music – especially in south Asia – often bases music on completely different frequencies and scales, e.g. an octave with 20 or 22 notes in the scale. Again, completely arbitrary.