reverse_transpose.ipynb

{
 "cells": [
  {
   "cell_type": "code",
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   "metadata": {},
   "outputs": [],
   "source": [
    "from music21 import *"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "def reverse_transpose(target_rootnote, note_to_transpose):\n",
    "    # midi number of the note to transpose and target rootnote\n",
    "    q = pitch.Pitch(note_to_transpose).midi\n",
    "    p = pitch.Pitch(target_rootnote).midi\n",
    "    # calculate midi number of equivalent note directly. earlier in transpose we did subtraction to calculate interval difference\n",
    "    x = q + p - 12 \n",
    "    # create a new Note object with the transposed pitch\n",
    "    transposed_note = note.Note()\n",
    "    transposed_note.pitch.midi = x\n",
    "    # get the name of the transposed note\n",
    "    transposed_note_name = transposed_note.name\n",
    "    # return the transposed note name\n",
    "    return transposed_note_name\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "F\n"
     ]
    }
   ],
   "source": [
    "notes_in_required_key=reverse_transpose(16,13)\n",
    "print(notes_in_required_key)"
   ]
  }
 ],
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