complete note conversion feature

[sugizo]

nice to have complete note conversion feature

e.g.
note_scientific = C4
note_helmholtz = c'
note = C
octave = 4
frequency_integer = 262
frequency_float = 261.6
midi = 60

ref
https://sugizo.pythonanywhere.com/music/master/pitch (for data gathered from wiki)
https://en.wikipedia.org/wiki/Musical_note (for explaination)

if you interest, can share the API data for note above from the web (sugizo.pythonanywhere.com/music)

best regards

[craffel]

PR welcome!