MIDI Note number and frequency

korakot (Korakot Chaovavanich) — Fri, 10 Feb 2006 08:27:27 GMT

Summary of MIDI Note Numbers
MIDI Note to Frequency

I can use them with my midi snippet.



# from http://logic-users.org/forums/L-OT/295

# Each note's frequency is 2^(1/12) times of the previous note.



freq = 440 * 2^((n-69)/12)

n = 69 + 12*log(freq/440)/log(2)



# Doe, ray, me, fa, sol, la, tee, doe

>>> play([(i, 100) for i in [60, 62, 64,65, 67, 69, 71,72]])

Generate and play midi on mobile phone

korakot (Korakot Chaovavanich) — Wed, 10 Aug 2005 00:37:27 GMT

From a previous snippet, you can play any sound file
(including midi) with pys60.
http://bigbold.com/snippets/posts/show/400

Now, what if you can generate a midi file as well?
I found a pure python midi file library.
http://www.mxm.dk/products/public/pythonmidi

I modify it a bit, just to make a single file for easy download.
http://larndham.net/service/pys60/smidi.py
With it, you can play a single note with the following code.



>>> import smidi

>>> m = smidi.MidiOutFile('C:\\out.mid')

>>> m.header()

>>> m.start_of_track()

>>> m.update_time(0)

>>> m.note_on(note=0x40)  # single note

>>> m.update_time(192)

>>> m.note_off(note=0x40) # stop it after 192

>>> m.update_time(0)

>>> m.end_of_track()

>>> m.eof()



>>> from audio import Sound

>>> s = Sound.open('C:\\out.mid')

>>> s.play()

>>> s.close()

These 10 lines can be made into a simple function.
Then, you can just type a line and play any note you like
on you mobile phone.



>>> from smidi import play

>>> play([(64,192), (32, 192)])

Ah... so pythonic. ^_^

DZone Snippets: midi code

MIDI Note number and frequency

Generate and play midi on mobile phone