Transpose MIDI To All Key Variations

MIDI_Transpose_To_All_Keys.py

#!/usr/bin/env python3
import sys
from music21 import *
from pathlib import Path

keys = [ "A" , "B" , "C" , "D" , "E" , "F" , "G" ]
key_modifiers = [ '####' , '###' , '##' , '#~' , '#' , '~' , '----' , '---' , '--' , '-`' , '-' , '`' , '' ]
key_modifier_names = [ 'quadruple-sharp' , 'triple-sharp' , 'double-sharp' , 'one-and-a-half-sharp' , 'sharp' , 'half-sharp' , 'quadruple-flat' , 'double-flat' , 'one-and-a-half-flat' , 'flat' , 'half-flat' , 'natural' ]

if __name__ == "__main__":
	input_midi = Path( sys.argv[ 1 ] )
	output_folder = input_midi.parent.joinpath( f"{input_midi.stem} - Keys" )
	output_folder.mkdir( exist_ok=True , parents=True )
	midi = converter.parse( str( input_midi ) )
	original_key = midi.analyze( "key" )
	original_key_tonic = original_key.tonic
	for key_index , key in enumerate( keys ):
		for key_modifier_index , key_modifier in enumerate( key_modifiers ):
			transposed_key = f"{key}{key_modifier}"
			if transposed_key == original_key_tonic:
				continue
			try:
				transposed_pitch = pitch.Pitch( transposed_key )
				transposition = interval.Interval( original_key_tonic , transposed_pitch )
				output_midi_file_path = output_folder.joinpath( f"{input_midi.stem} - {transposed_key}.mid" )
				output_pdf_file_path = output_folder.joinpath( f"{input_midi.stem} - {transposed_key}.pdf" )
				transposed_midi_file = midi.transpose( transposition )
				transposed_midi_file.write( "midi" , fp=output_midi_file_path )
				# transposed_midi_file.write( "pdf" , fp=output_pdf_file_path )
				print( f"Transposed from {original_key_tonic} to {transposed_key} === {key_modifier_names[key_modifier_index]}" )
			except Exception as e:
				print( key_index , key_modifier_index , e )