"Which Twenty-Six Notes"

Sorry....This will probably "bore the pant's" off a few people but here goes:-

I've mentioned a couple of times that I have a 26 note Street Organ.

I built it myself over a period of three years: It was a sort of retirement project.

The organ has 70 wooded pipes but can only sound 26 notes. This is because the Tracker-bar has only 26 holes. The Tracker-bar is the bar which runs across the paper roll (or card book) at 90 degrees to the movement of the paper, and tracks the holes punched in it.

The 26 notes are not consecutive tones or semitones, but are 26 chosen from a consecutive run of 35 semitones.

This run starts on the Eb below middle C, and finishes up, 35 semitones higher on Db.

Now......which 26 notes do you pick? 

Well over the years different manufactures have had different ideas on this. So we now have dozens of different "standards". Not only do we have large organs with 101 keys (ie Hooghuys), and 112 keys (ie Mortier Dance Organs), but we also have them choosing different scales.

However, back to the 26 from 35 choice. 

There are 12 semitones in an Octave and it is usual to only sing 8 of these. Therefore to sing or play most SIMPLE tunes, we only need 2/3 of the notes. This is like, "only playing the white notes" on the piano.

My small organ, has pipes divided into 3 groups.

 1)   The highest are the Melody pipes, and here we have chosen 13 (of the 14 highest) so only one note ( B natural) is missing. These are the pipes on show in the front.

 2)   The lowest are the Bass pipes, there are 5 of these, chosen from the lowest 10.

 3)   The remaining pipes, between groups 1) and 2) are known as the Accompaniment. There are 8 of these chosen from the remaining 11.

So.....we have 13+5+8=26 chosen from 14+10+11=35.

To summarize then, we have almost a full set of Melody pipes, to play the "tune" or "melody". We have 5 Bass pipes and 8 Accomp. pipes to play along under the melody.

These bass and accomp. pipes are chosen to make the best arrangements in the key of Eb. All the notes are there for the bass and major triads. It is also possible to play in Ab or Bb, with just a few notes missing.

.....and at a stretch, in Db or F, with a couple more missing.

I have just arranged "The Arrival of the Queen of Sheba" by Handel, so it just goes to show what you can do with 26 well chosen notes.