y-usuzumi / dechorder

Mirror of https://gitlab.com/tospio/musician/dechorder (private for now)

dechorder

A library that aims to be a complete MIDI composition toolkit

Features

• A stupid pitch and interval parser
• Absolute pitch and interval arithmetic
• Pitch to frequency conversion under a given tuning system (now supports 12-equal temperament)

Guide

• Playing with pitches and intervals

import TOSPIO.Musician.Notation.IPN
import TOSPIO.Musician.Notation.IPN.Parser

main :: IO ()
main = do
  let p = pp "A#4"           -- Pitch (4, PitchClass (A, [Sharp]))
      majorThird = ip "3M"   -- Major third
      p' = p <:+ majorThird  -- Pitch (5, PitchClass (C, [Sharp, Sharp]))
  print $ showReadable p'    -- "C##5"
  
  print $ map showReadable $ take 12 $ iterate (<:+ ip "5") $ pp "C3"  -- Circle
  of fifths

• Pitch to frequency

import Data.Proxy
import TOSPIO.Musician.Notation.IPN
import TOSPIO.Musician.Notation.IPN.Parser
import TOSPIO.Musician.Tuning

main :: IO ()
main = do
  let p = pp "A#4"           -- Pitch (4, PitchClass (A, [Sharp]))
      majorThird = ip "3M"   -- Major third
      p' = p <:+ majorThird  -- Pitch (5, PitchClass (C, [Sharp, Sharp]))
  print $ toFreq (Proxy :: Proxy EqualTemperament) (pp "A4")    -- "440.0"
  print $ toFreq (Proxy :: Proxy EqualTemperament) (pp "C5")    -- "523.2511306011972"