MIDI Note Numbers & Octave Names

Acronym: Musical Instrument Digital Interface

There seems to be some confusion on various websites about MIDI note names and numbers.  I've done a little research into the subject and reached these conclusions which I hope will not confuse even more.

MIDI Note Numbers

We all know note names as C, Bb, D# etc. and can easily work out which octave they are in by looking at the music notation, however, computers and MIDI devices are not quite as intelligent as us!  These instruments need something more precise, so each note has been given a specific MIDI number 60, 70, 75 etc., middle C being 60 incrementing by one for each semitone increase in pitch.  All MIDI devices use these numbers.

Octave Names


Notes are also given names based on the octave in which they occur - this is where the confusion starts!  The standard piano keyboard has 88 notes each one being a semitone apart. Starting at the lowest C on the piano keyboard this is usually referred to a C1 making middle C, C4, as it starts the fourth octave.  Some musicians refer to the low C as being C0, middle C then becomes C3.  As you will see when I refer to keyboards as opposed to pianos it would probably be more sensible to do this.

Which ever octave name is given to middle C its pitch is always the same, i.e. 261.63 Hz., (to nearest two decimal places).  The piano usually has a few notes below the lowest C as shown in the diagram.

To make the situation worse other musicians will start the octave at A, making this A1, as it is the lowest note on the piano.  However, this does not alter the octave numbering of the notes C as in the diagram above, but it does mean is that A1 and B1, above, now become A2 and B2 and so on.   Others make the lowest A, A0.  Hence the confusion.


The modern keyboard has fewer notes, usually beginning at C, two octaves below middle C, as do most keyboards.  Keyboard players using MIDI sequencers may refer to their lowest C as C1, which then makes middle C C3, the same as the piano with the low C at C0.  This is the case with my Yamaha® Tyros4 work station

In one MIDI sequencer I use, the octave names are as shown on the Piano Roll display window.  However, the programmers, no doubt realising the dilemma outlined above, have made it possible to set up the Base Octave, in the initialisation file, to whatever you wish by using a positive or negative number.

What a mess!!!......         Still confused?   Me too!!!

20 Note Raffin Scale

The red dots on the graphic above indicate which notes are used on the 20 note Raffin scale used by the John Smith Busker and Senior Organs.  These notes permit music to be played in the keys of F major and Bb major, and their relative minor keys of D minor and G minor respectively.  With some tunes the upper range might be inadequate so these notes have to break back an octave.  This can be noticed on commercially produced rolls, but is quite acceptable.

As there is only one accidental in each key  Eb or E, depending on the key in which you are playing, music almost certainly has to be modified to accommodate this limitation.


How many roads must a man travel down - until he admits he is lost?