For example early or contemporary programmers may assume that an octave is doubling of frequency.
(Later addition: The MSX MUE music editor sending to the AY sound generator may have good sounding octaves, there are at least 2 YouTube videos).
It is close but it is not. Human brain perceives a doubling of frequency as a flat octave [Terhardt]. Even more so at higher intensity since pitch depends on intensity [Stevens].
Frequency is measured in Hz (no of vibrations per second, from the name of the physicist Hertz). Pitch, the human brain perception of height of tone is measured in Mels (from the word melody).
Perhaps it is stating the obvious but computer programming for musical purposes has to be done by human brain ear or brain. Or the user given the tools to program each note, such as on Yamaha DX77ii or Korg Triton [euroelectron].
Now that tools exist musical temperament should be adjusted for the particular musical key used in a composition. Frequency relation of overtones of instruments adjusted too for best or harmonic relation to human brain, (if the fond harmonic is x2 it sounds flat). Exactly the same principles as on good, say Steinway pianos or good quality orchestra or choir intonation.
References:
Streched (engineering) octaves - Terhardt
Sound and Hearing - Stevens, Warshofsky - Time Life science series - chapter 5, The mind's Influence, page 77
The Pleiades equal pitch temperament for DX7 or Triton - euroelectron
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