III
In connection with the foregoing it will be interesting to learn the specifications of the principal organs of which Bach was able to avail himself during his long career. We find details concerning them in various works, notably in Adlung (Musica mechanica organoedi), or in the supplement which J.F. Agricola, an esteemed pupil of Bach, added to this work, published after the death of its author; and in the contemporary writings of local historians.
The organ at Arnstadt, the first at which Bach held the position of organist, possessed twenty-four registers, divided among two manuals and the pedal:[179]
Great Organ.
| 1. | Principal, | 8' |
| 2. | Viola da Gamba, | 8' |
| 3. | Quintatön, | 16' |
| 4. | Gedackt (Bourdon), | 8' |
| 5. | Quinte, | 6' |
| 6. | Octave, | 4' |
| 7. | Mixtur, 4 ranks | |
| 8. | Gemshorn, | 8' |
| 9. | Cymbel, 2 ranks | |
| 10. | Trompete, | 8' |
| 11. | Tremulant | |
| 12. | Cymbelstern[180] |
Choir Organ.
| 1. Principal, | 4' |
| 2. Lieblich Gedackt, | 8' |
| 3. Spitzflöte, | 4' |
| 4. Quinte, | 3' |
| 5. Sesquialter | |
| 6. Nachthorn (night horn), | 4' |
| 7. Mixtur, 2 ranks |
Pedal Organ.
| 1. Principalbass, | 8' |
| 2. Subbass, | 16' |
| 3. Posaunenbass (trombone), | 16' |
| 4. Flötenbass | 4' |
| 5. Cornetbass, | 2'[181] |