chordid~

This external implements the Chromagram/ChordDetector by Adam Stark. (https://github.com/adamstark/Chord-Detector-and-Chromagram)

I have extensively modified the ChordDetector code to change the classification scheme, and have extended the range of detectable chords. This may create errors of classification - please let me know if you find any.

My thanks also to Fabrizio Poce (J74 Harmotools), who reviewed my initial VST implemention. This external is much better, I think. I'm glad I came back to it. http://fabriziopoce.com/HarmoTools.html

I have also used the maxmpp C++ template as the basis of this external. https://github.com/grrrwaaa/maxcpp My thanks to Graham Wakefield for this template - it made my introduction to Max/MSP external programming much easier.

Any issues with the code are mine: please contact me if you have queries or suggestions for improvement.

It has a single signal inlet/outlet acting as a passthrough. inlet messages: bang resend last chord data on data outlets rate this sets the number of 512 sample frames the Chromagram detector waits before generating a new chromagram. Default is 1 for the most rapid response. Increase this to reduce CPU use. rms this sets a cutoff volume to prevent noise generating random chords.

outlet messages 0 : signal passthrough 1 : chord name text symbol with the chord name 2 : chord number this is a 12-bit chord type, plus the root_note value * 10000 root_note values use C = 0 the chord type is C rooted chord ... C C# D D# E F F# G G# A A# B Major 1 0 0 0 1 0 0 1 0 0 0 0 = 2192 Minor 1 0 0 1 0 0 0 1 0 0 0 0 = 2320 7th 1 0 0 0 1 0 0 1 0 0 1 0 = 2194 and so on ... e.g D7th would be root_note D = 2, * 10000 = 20000, + 2194 = 22194 Em root_note E = 4, * 10000 = 40000, + 2320 = 42320

It is relatively easy to extract suitable information from this format.
Some enharmonic chords may be incorrectly classified 
  e.g Dsus4 is enharmonic with Gsus2
This cannot yet be avoided, but I have some future ideas.

3 : list of MIDI note values from middle C (60) the note values produce a chord that is the same as the detected chord

4 : rms_cutoff this is 0 if the input is below the cutoff value, and 1 if the chord detector is active on the input stream.

Licence:

• This program is free software: you can redistribute it and/or modify
• it under the terms of the GNU General Public License as published by
• the Free Software Foundation, either version 3 of the License, or
• (at your option) any later version.
• This program is distributed in the hope that it will be useful,
• but WITHOUT ANY WARRANTY; without even the implied warranty of
• MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
• GNU General Public License for more details.
• You should have received a copy of the GNU General Public License
• along with this program. If not, see http://www.gnu.org/licenses/.