Convert Midi Note Numbers To Name and Octave

Jon picture Jon · Apr 3, 2009 · Viewed 12k times · Source

Does anybody know of anything that exists in the Java world to map midi note numbers to specific note names and octave numbers. For example, see the reference table:

http://www.harmony-central.com/MIDI/Doc/table2.html

I want to map a midi note number 60 to it's corresponding note name (MiddleC) in octave 4. I could write a utility class/enum for this, but it would be rather tedious. Does anybody know of anything?

I'm specifically using this to write a Tenori-On/Monome clone in Java, so far so good...

Solution

This was what I ended up using:

String[] noteString = new String[] { "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B" };

int octave = (initialNote / 12) - 1;
int noteIndex = (initialNote % 12);
String note = noteString[noteIndex];

Answer

paxdiablo picture paxdiablo · Apr 3, 2009

I'm not convinced your suggestion is that tedious. It's really just a divide-and-modulo operation, one gets the octave, the other gets the note.

octave = int (notenum / 12) - 1;
note = substring("C C#D D#E F F#G G#A A#B ",(notenum % 12) * 2, 2);

In real Java, as opposed to that pseudo-code above, you can use something like:

public class Notes {
  public static void main(String [] args) {
    String notes = "C C#D D#E F F#G G#A A#B ";
    int octv;
    String nt;
    for (int noteNum = 0; noteNum < 128; noteNum++) {
      octv = noteNum / 12 - 1;
      nt = notes.substring((noteNum % 12) * 2, (noteNum % 12) * 2 + 2);
      System.out.println("Note # " + noteNum + " = octave " + octv + ", note " + nt);
    }
  }
}