I know of no collection of instrumental compositions in which the individual works have less in common than the Brandenburg Concertos. Strange though it may seem, it is this very diversity which welds them together. Each concerto is basically written for a different combination of instruments and their formal dissimilarities are as great as those in scoring or style. In his dedicatory score addressed to the Margrave of Brandenburg Bach seems almost to have provided a sample catalogue indicating his range as an instrumental composer, in which he was clearly aiming at the greatest possible variety. As has recently been demonstrated, he did not compose the six concertos specially for the collection, but compiled it from the repertoire of the orchestra at Cöthen.
While the instrumental combinations - brass, woodwind, strings, harpsichord - employed in Concertos Nos. 1, 2, 4 and 5 are of a diversity which borders on the bizarre, bearing in mind the time when they were written, Nos, 3 and 6 are exclusively for strings. Concerto No. 3 presents the whole violin family. I know of no other work in the entire repertoire which adheres so rigidly to the principle of presenting one particular type of instrument; three violins, three violas and three cellos, accompanied by a continuo consisting of violone (double bass) and harpsichord. This suggests an obsession with numbers; moreover, the tutti sections are always in three parts, and each part is divided among three instruments.
All possible permutations of the solo and tutti principle are exploited and presented in this concerto, from the true solo of a single instrument, via the accompanied solo and the concertante dialogue of the various groups of instruments, to the three-part tutti, in which the three instruments within each of the three groups play in unison as though in an orchestra. In the first tutti (up to bar 8) each group begins with a different motif; these three motifs, together with another for the first violin which is not introduced until bars 78/79, provide the material which, by way of exchanging parts, division and variation, imparts to this movement a tremendous harmonic and rhetoric richness. Each of these motifs is itself subdivided, just as in speech main and subordinate clauses are separated from one another by punctuation marks. This type of demarcation is to be found, for example, in the middle of bar 2, at the beginning of bar 4, etc. Thus, for instance, even within the first eight bars there are several changes from staccato to legato, just as the utterance of the various parts of a sentence calls for differing degrees of hardness and softness. This requirement of 18th century teaching practice is met again and again in the complex themes of the great works.
The first solo (anacrusis in bar 9 to bar 12) consists of a version of the first violin motif, harmonised by the solo instruments and broken down into its smallest constituent parts, which moves through all three groups. The 2nd to 5th quaver in bar 10 is a tutti interjection, to which the violins respond with a new solo scale motif (middle of bar 10 to bar 12), while the cellos and violas provide the accompaniment in the shape ofa harmonised variation of the second part of the original bass motif (middle of bar 2 to bar 4). In bars 12 to 15 this solo episode is replied to by the second half of the opening tutti (bars 4 to 8). The second solo, which now follows (middle of bar 15 to bar 19), is similarly constructed to the first one: once again the tutti interrupts (2nd to 5th quavers of bar 17), although here and in the succeeding scale motif the violas play the violin part of the first solo passage, while the violins and cellos play a variant of the harmonised bass motif as an accompaniment. In the opening bars of the following tutti (bars 19 and 20) the parts are changed round, the violas playing the violin motif and vice versa; the cellos continue for the time being to play their own motif.
These brief explanations are intended to point out an aspect of the structure of these concertos which does not get much attention, and which to my mind highlights the comparison and contrast of the three different forms of "violin"; moreover they emphasize Bach’s skill at making a clear distinction, in a work in which each part is taken only by a single player, between the solo and tutti sections, even though all instruments are playing continuously, in other words by purely musical means.
In this concerto Bach dispenses with the slow movement; the two allegro movements are linked by two chords, possibly intended to frame a short improvised cadenza which, in this concerto for strings alone, could only be played by one or more string soloists.
In the second allegro there is virtually no dialogue - most unusually for a baroque concerto. The harmonies shift kaleidoscopically half-way through the bar or in crotchets (the 12/8 metre is to be understood as being 4/4 in triplets); scurrying semiquaver scales, bell-like repeated quavers and intricately interlocking spiccato semiquaver triads leap to and fro between the voices. Only in the second half (bars 15 to 17) are there any concertante solo passages for the first violin, and (bars 35 to 37) for the first viola.
The Brandenburg Concerto Nr. 5 is the most modern of the six, both in instrumentation and in form. It is the first true keyboard concerto in the history of music. The other two solo instruments, clearly subordinate to the harpsiehord, are the violin, the solo instrument par excellence since its development, and the flute, which at that time was just beginning to supplant the brilliant recorder, probably because the ”galant“ and "empfindsam“ styles were coming into fashion. Thus the flute was thoroughly modern as a solo instrument, its somewhat veiled sound and tonal and dynamic nuances being ideally suited to the new fashion; until then its scope had by no means been fully recognised, let alone exploited. During the course of the 18th century the flute developed into the most popular of all solo instruments.
In order to appreciate the sensation that the use of the harpsichord in this concerto must have produced and what creative boldness inspired Bach with this idea, one must recall its customary role at the beginning of the 18th century. It was used exclusively for solo music like the organ and, indeed, was interchangeable with it. Predominantly the music for it was polyphonic, written in strict style; at that time nobody had yet envisaged a keybord instrument as a melodic instrument. It was also used, in chamber and orchestral music as well as in opera, in the continuo, i. e. it played the bass line, filling out and clarifying the harmonies. On account of its metallic, plucked sound it also had the happy side effect of structuring the rhythm, which was necessary for much of the music of the 17th and 18th centuries. Because its sound was so prominent in the ensemble there were rules for playing the continuo, which required that it should always stand back modestly, it should fill in the accompaniment but should never obtrude - not even by artistry, let alone virtuosity; imagination had to be displayed in the style of playing, in the legato and arpeggio. Bach now let the harpsichord, and incidentally himself as its performer, undertake for the first time the "experiment" of both playing solo and accompanying a small orchestra and two other soloists. He devised a musical language particularly appropriate to this instrument; by assigning to the violin and flute the same motivic Brandenburg Concerto No. 6 is as unique and basic in regard both to instrumentation and style as is No. 3. Contrary to every baroque tradition it is scored only for the low register: two violas are the solo instruments, and in the tutti the predominant role is allotted to two violas da gamba. Violas and gambas have approximately the same range, therefore Bach must have deliberately set these two representatives of the rival families of instruments - the violin and the viol - against each other. Indeed, from the middle of the 17th century onwards the gamba had next to the violin been the most highly regarded solo instrument. Its timbre was compared to the “nasal voice of a diplomat“; it was never used in the orchestra; Bach himself wrote only solo parts for the garnba, except in Brandenburg Concerto No. 6. And now this aristocratic solo gamba was relegated to the role of a plebeian tutti instrument by the viola, a genuine orchestral instrument for which, until then, no solo music had been composed and which was totally unheard-of as a virtuoso instrument (as in the first and third movements) or as an expressive instrument (as in the second movement). During the first half of the 18th century there existed an intense rivalry between the upper-class gamba, which was played delicately and uasally in the drawing room to a select audience, and the violin or cello whose loud, extrovert timbre was suitable for large halls or even the open air. Again and again writers bemoaned the fact (Le Blanc “In defence of the Viola da Gamba") that the brutal and vulgar violins, with their coarse strings, were supplanting the gamba. Here Bach highlights the victory of the violin family by having the gamha deposed not just by the violin, but by the most lowly member of the species, the viola.
In this concerto, too, the differentiation between solo and tutti sections is achieved primarily by musical and dynamic means and not by true solo playing. There is a clear distinction between the solo and tutti motifs. The first tutti is essentially a relentless, indeed almost brutal, battle waged by the two violas over the correct metre. The two parts chase one another only a quaver apart, creating the impression that each of them is determined to win the battle for the strong beat. The other instruments accompany them in entirely neutral, ruggedly stamping quavers (only Bach could afford to employ this out-of-date style), as though unwilling to take sides. All six tutti sections of this movement are constructed strictly in accordance with this principle.
In the first solo, introduced by the cello in bar 12, the elegance and the dynamics are determined by the gambas which are playing in imitation and thus participate in the solo work, which otherwise is divided between the violas and the cello. The second solo ends (bars 40-46) with a new interpretation of the first solo motif.
By writing an anacrusis of a seventh (in place of the rising fourth), by dispensing with continuous imitation in the other voices and by accompanying the motif with gentle chords (bow vibrato, played piano) Bach achieves a true, supremely expressive, cantabile solo passage which contrasts quite strikingly with the following tutti. The techniques with which Bach manages to wrest the greatest possible contrast from an ensemble which is particularly homogeneous to start with are truly remarkable.
The last tutti repeats the first, like a da capo, except that it starts half a bar later. This displacement, which is not uncommon among Bach`s works (but is also to be found in the symphonies of the Viennese classics) proves that the metre is not altogether dependent on the bar line. In this case the stresses must be the same in the first and last tutti; no doubt Bach merely refrained from inserting a 2/4 bar before the last tutti (half-way through bar 114) for reasons of notational convention.
In the second movement the two violas compete with one another above a most interestingly divided bass; the violone (double bass) and the harpsichord (presumable also an octave below) are given a bass line conceived as a counterpart played by the cello in diminution in andante crotchets, resulting both in some gripping passing dissonances and a firm rhythmic pace for the whole movement. Towards the end (from bar 40 onwards) the theme wanders into the bass line, to which the violas react with a kind of amazed confusion; finally the cello takes over - one might almost say usurps - the cadence in bars 54 and 55, taking the movement to the end with an interrupted cadence that paves the way for the allegro finale.
Here, as in the first movement, in the opening tutti rhythm and metre are both strongly delineated and yet called into question; though the movement begins with an anacrusis, this is tied across the bar line to the third bar, creating a syncopation which makes it appear that the violas are starting the bar on the last quaver. The other instruments play energetic chords on the beat, thereby causing an argument about the correct metre. In this movement the gambas are completely excluded from the solo work which is primarily allotted to the violas, although the cello also gets its chance.
In conclusion, a few remarks about the violone. In the 18th century the term “double bass” was rarely used; as a rule the largest member of both the violin and the viol family was called the “violone”, but frequently the term was also employed for the cello. In order to make confusion worse confounded, some early l7th century German sources described only the sixstringed double bass viol as a violone, and this specific nomenclature has unfortunately been adopted by many authors of the present day. In view of the paucity of contemporary sources, if any clarification is to be obtained it can only come from the music itself and not from the nomenclature. The main problem, of course, is whether the violone part is to be played as it is written, like the cello, or an octave lower, like the double bass. In the Brandenburg Concertos this question turns up again and again in all its aspects, since Bach by no means dealt consistently with the ”violone“ part. Thus in Concerto No. l the part is described as “violone grosso" and is always notated at the same pitch as the cello and bassoon. Bach wrote il on the bottom stave together with the continuo - presumably harpsichord (8'). In Concerto No. 2 it is called a “violone ripieno", i.e. orchestral bass. This part occupies the penultimate stave, because the bottom stave is reserved for the harpsichord and the cello; this work contains a number of solo passages which Bach evidently did not want to be accompanied by the “violone“.
I think Bach intended all six concertos to have real double basses, which originally are likely to have been different or at least differently tuned instruments, because the violone parts are written in such very divergent ways. For example Bach used a double bass with a low C for Concertos Nos. l, 2 and 3; in Concertos Nos. 4 and 5 the lowest note on the instrument was evidently the contra D, which may be concluded from the fact that some phrases have been put up; in Concerto No. 6 Bach even wrote a sub-contraB flat (last movement, bar 45); for this movement, if not for the whole concerto, the contra C string had to be tuned down, which is what we have done in this recording.
Since the double bass part is usually derived from the continuo hass (cello, bassoon, harpsichord) without any further differentiation, the part written out in full in the Brandenburg Concertos is especially informative. There are instances (e.g. bars 25/26 and others in No. 2) where Bach writes the cello and bass parts an octave apart; in the double bass part this produces double octaves, although this is not usually apparent nowadays because most double basses do not go below the contra E and players tacitly transpose everything below that note to the octave above. This very significant and striking effect occurs in Concerto No. 4 (bars 29/30, 154-156), in No. 5 (many instances) and in No. 6. In the latter two there is even a gap of three octaves (No. 5, bar 134; No, 6 bar 65 ff), Occasionally the continue part is notated in the upper octave, which results in unison; sometimes it is even written two octaves higher, so that the double bass sounds an octave higher than the cello.
This score indicates, therefore, which instruments Bach had at his disposal or wanted (clearly there was a variety), and how he handled the different registers (8’ as written, 4’ one octave above, l6’ one octave below, 32’ two octaves below the cello part).