A. Discover the principals on the organ(s) you play. They may have names such as Diapason, Open diapason, Principal, Prinzipal, Montre, Octave, Prestant, Super Octave, Fifteenth, Geigen Diapason, Violin Diapason, etc. Once you think you have located them, you will notice that they typically have a number associated with them, such as 32’, 16’, 8’, 4’ and 2’ (and even 1’). There are other numbers which will be discussed a little later.
B. Play each of these stops alone in each of the five octaves of the keyboard and note the quality of the tone – loudness, color, texture, overtone development, attack/release, transients, etc. Check to see if there are any other “principal tone” stops with names other than those given above.
C. Next, try playing the four parts of a hymn using each stop, playing it in a range of the keyboard where singers may be able to sing with you. This will reveal to you the individual stop’s ensemble characteristics as well as its voicing, tuning and regulation.
Playing the chromatic scale from bottom to top will show you where the stop is strong and where it is weak. Compare this to the strong and weak areas of the other principals.
D. To create a “Chorus,” begin with the lowest pitched Principal or Diapason. (On the manuals, begin with the 8’; if there is no 8’ Principal tone, start with 8’ Flute Tone) As you play a hymn, add the next higher pitched principal; then another until you have added all the principals on the division (Swell, Great, Choir, Positiv, Pedal, etc.)
For further investigation, couple all the manuals to the Great and Pedal and explore which additions from the various divisions will take the entire ensemble the next step further in a smooth and pleasant manner. Hint: Start with the quietest of the 8’ principals and build gradually.
E. Repeat the investigation with the other classes of tone.