galibhassan / sacred-music

Eastern to Western musical notation converter

SaCReD Music

A package to convert eastern to western musical notation, for example, SA RE GA ma to C D E F.

Installation

npm install --save sacred-music

Description

This node package provides a functionality which takes eastern notations either in Bangla (Bengali) or English alphabet, and converts into western notations in English alphabet.

Melodies of Bangla songs are commonly confined within three octaves:

• Lower octave ( Mondro Shoptok or মন্দ্রসপ্তক ),
• Middle octave ( Moddho Shoptok or মধ্যসপ্তক ),
• Upper octave ( Tara Shoptok or তারাসপ্তক ).

Middle Octave

In this package, we have denoted the 12 notes of the Middle Octave as:

SA re RE ga GA ma MA PA da DHA ni NI

or

সা ঋ রে জ্ঞা গা মা হ্মা পা দা ধা ণি নি

Lower Octave

The 12 notes of the Lower Octave is denoted by putting an Underscore ( _ ) as suffix to the any note of the middle octave. Hence the notes are:

SA_ re_ RE_ ga_ GA_ ma_ MA_ PA_ da_ DHA_ ni_ NI_

or

সা_ ঋ_ রে_ জ্ঞা_ গা_ মা_ হ্মা_ পা_ দা_ ধা_ ণি_ নি_

Upper Octave

The Upper Octave 12-notes are denoted by suffixing a middle octave note by an Asterisk ( * ). Hence:

SA* re* RE* ga* GA* ma* MA* PA* da* DHA* ni* NI*

or

সা* ঋ* রে* জ্ঞা* গা* মা* হ্মা* পা* দা* ধা* ণি* নি*

The Tonic

The tonic string should be specified by the user. Below, we present the writing convention of chromatic scale for C5 :

Note (5th octave)	String
C	'C5'
C♯/ D♭	'Cs5'
D	'D5'
D♯/ E♭	'Ds5'
E	'E5'
F	'F5'
F♯/G♭	'Fs5'
G	'G5'
G♯/A♭	'Gs5'
A	'A5'
A♯/B♭	'Bf5'
B	'B5'

For different octaves, just change the octave-number, e.g. 'C1', 'C2', etc.

API

• function relativeToAbsolute( inputNoteString, tonic )

  Input inputNoteString : String - any string containing eastern notes, tonic : String - a tonic string (see the table above).

  Returns Western notes in an Array corresponding to inputNoteString.

  Example

  var sacredMusic = require('sacred-music');
  var notes = 'SA RE GA ma পা ধা নি সা*';
  var tonic = 'C4';
  var output = sacredMusic.relativeToAbsolute(notes, tonic);
      
  console.log(output);
  // Expected console-output:
  //  [ 'C4', 'D4', 'E4', 'F4', 'G4', 'A4', 'B4', 'C5' ]

• function getSongDetails( inputNoteString )

  Input inputNoteString : String - any string containing eastern notes.

  Returns an object, say, songDetail which contains:

  • noteList: Array - The list of all notes from user input (sequentially),
  • noteSet: Array - The Set of unique notes, i.e. no notes occuring twice in this array,
  • bars : Array of arrays - Each element is an array and represents a Bar. Bars (also called measures in literature) are seperated by a slash ( / ).
  • noOfBars: Integer - Number of bars in the song.
  • barsWithNoteCount: Array of arrays - Each element is a subarray. An elements of a subarray represents the number of notes located in that specific position.

  Example

  var sacredMusic = require('sacred-music');
  var notes = 'sa+re ga sa+re ga / re+ga+sa ga re sa / ga re sa re';
  var songDetail = sacredMusic.getSongDetails(notes);
  console.log(songDetail);
  
  // expected output:
  { 
    noteList: [ 'sa','re','ga','sa','re','ga','re','ga','sa','ga','re','sa','ga','re','sa','re' ],
    noteSet: [ 'sa', 're', 'ga' ],
    bars: [ 'sa+re ga sa+re ga', 're+ga+sa ga re sa', 'ga re sa re' ],
    noOfBars: 3,
    barsWithNoteCount: [ [ 2, 1, 2, 1 ], [ 3, 1, 1, 1 ], [ 1, 1, 1, 1 ] ] 
  }

  Notice, for example, (songDetail.barsWithNoteCount[1])[0] = 3 corresponds to re+ga+sa in the input string.

Invalid input

If the you input an arbitrary string which does not contain any of the easter notes, dont worry. It will report the invalidity of the note with an error message.

FAQ

• Why on earth it is named sacred music? Does it have anything to do with religion or so?

  Nope. In fact if you take C as tonic, then SA converts to C and Re converts to D. Now guess, why it's sacred! And music is because somebody already published a node package with the name sacred. Alas! Feel free to stick to the faith that it is something sacred if you haven't still crunched the riddle. ;-)