During the concerted music, the organist had to accompany from figured bass, and the voice part was rarely given him, as the cantor would not trouble to write it out, though Bach, with his characteristic thoroughness did so in many cases.
Bach’s method of playing from figured bass
There exists a specimen of Bach’s method of playing from figured bass in a MS. accompaniment to a violin sonata of Albinoni, by H. N. Gerber, a pupil of Bach.[83] It contains a few autograph corrections by Bach himself, and it may be taken, therefore, as an example of the manner which Bach approved of. It is described by Spitta as of no melodic character, as being in four parts throughout, and as not adhering strictly to the harmonies given by Albinoni where an improvement was possible. The adornment of a figured bass accompaniment by a melody in the right hand was only possible to the greatest artists, such as Bach himself; and it soon went out of fashion.
During the seventeenth century it was the custom for performers to elaborate the melody written by a composer, and naturally Bach’s were treated in this way. But it was complained that he left little for the performer to add, for he “indicated all the manieren, the small ornaments, and everything else that is understood by ‘Method’ in playing, by actual notes,” and the performer could therefore not impress his own individuality on the piece.[84] Bach was particular to show exactly what he required; and it is evident that there was at this time a school of musicians rising, who objected to superfluous ornaments on the part of the performer. J. S. Petri objects to extemporised shakes and right hand melodies. Scheibe objects to contrapuntal accompaniment. Kirnberger says that the accompanist should aim at simplicity, and only add such ornaments as were absolutely necessary.
If the pedal was employed, the left hand helped with the harmonies. But if the bass moved rapidly the pedals only played short notes to mark the essential harmonic progressions; or the bass was even omitted, as the other instruments played it. For accompanying the solo voices in arias and recitatives the Gedact 8 feet was usually used alone, and was sometimes therefore called the “Musik gedact”: it is the same as the English stopped diapason. The chords in a recitative were not held long, even if the bass notes were. They were played arpeggio, as on a harpsichord. But Petri considers that if there is a very soft stopped flute, the chords may be held in the tenor register and the changes of harmony indicated by a short pedal note.
Organ-playing
Staccato playing was universal on the organ, but Bach and his pupils insisted on a legato style, and gradually eliminated the staccato, though in accompanying they still kept to it. The tradition of Bach’s style of accompaniment was carried on by Kittel a pupil of Bach, who spread the knowledge of it through Thuringia, and one of Kittel’s pupils, M. G. Fischer of Erfurt, continued it. He died in 1829, and was heard by Grell of Berlin (b. 1800, d. 1886), who described the performance to Spitta. He played the bass with considerable power, and accompanied it by short chords in the right hand on another manual, thus agreeing with Petri’s direction that the organist is to accompany in as short a style as possible, and to withdraw the fingers after striking the chord.
But this was by no means Bach’s only method of accompanying, for he demands in the majority of cases a legato accompaniment, and sometimes a “melodic” manner. In his Matthew Passion and some of his cantatas the organist is to play short chords in recitativo secco.
He considered the Gedact peculiarly adapted for purposes of accompaniment; and in many passages he dispensed with part or the whole of the bass instruments.
In order not to drown the voices, or make the organ too prominent, no reeds or mixtures were allowed to be used in accompanying. They were reserved for solo organ work, in which Bach made use of astonishing combinations of stops. Orchestral effects were produced by the contrasts of tone-colour in the different groups of instruments, string, brass, reeds and flutes. To these the organ, making use of diapason work only, formed a background, and it was not allowed to predominate over them.