The Brandenburg Concerti are in fact a selection from the music Bach composed for the court orchestra, the Hofkapelle, during his time at Köthen. Bach dedicated these six concerti, which had all been composed some time before, to the Margrave of Brandenburg, and took the opportunity to write all six into a combined dedicatory score. What I feel is important here is that the concerti were not, as was usually the case, adapted to the musical abilities of the dedicatee; rather, they represent a colourful pattern book of the composer’s art.
One must bear this in mind to explain the remarkable fact that these concerti have nothing whatsoever in common exccpt the names of the composer and the dedicatee - as individual works they are as different as was conceivable at the time: each concerto is scored for a different combination of instruments and soloists; Bach follows different structural principles in each case. The concertante playing of a soloist or group of soloists as a dialogue or contest with a ripieno group - in this case a small string orchestra - is occasionally reduced here to a purely formal, only musically recognisable idea (for example, in the slow movement of concerto no. 5 or in the entire 3rd and 6th concerti). These six concerti, then, represent in every respect the maximum possible differentiation and variety. Diversity takes precedence over uniformity.
Brandenburg Concerto no. 1 is one of the earliest works in musical history in which the hand horn is employed as a solo instrument across the entire breadth of its capabilities. The entry of this instrument into the intimate sphere of refined salon music must have created a sensation. The hunting horn (corno di caccia) was principally used in hunting, different horn signals serving to keep the widely scattered groups informed on the progress of the hunt. This genuine “open-air" instrument was blown mainly by the huntsmen themselves and their attendants. Even the horn-players in the first performances of Bach’s concerto may well have been travelling “huntsmen-virtuosi”; this is, at all events, made very clear by their entrée in the first tutti, a real hunting fanfare, in which the quavers are adapted to the triplet rhythm characteristic of the hunt. The rest of the orchestra, apparently unmoved by the horn signals with their quite unwonted form and rhythm, plays a quite "normal" Bachian orchestral tutti. The concertante playing already stands out here with the alternating of the oboes and strings in bars 6-7; from bar 9 onwards the horns are brought in as full concerto partners, and Bach uses the intonationally extreme natural notes F, F sharp and A (the eleventh and thirteenth harmonics) from the start. Since the musical sound groups of "figures" in this movement correspond to common, well-known forms, Bach was able to leave the very necessary articulation up to the musicians. We therefore put in and performed the articulation markings according to contemporary usage. In the first movement the concertante playing comes out, between real tutti blocks, as a confrontation (something of a vehement dialogue) beetween the three groups horns, woodwind and strings. In the second movement the solo oboe, the violino piccolo (a small violin, tuned a minor third higher, which produces an odd, acute sound) and the bass group imitate each other on a refined, impressionistic basis. Here the most unusual articulation is specified by the composer. The first four bars belong to the solo oboe, whose notes, determining the harmony, are harmonically reinforced by the second and third oboe and the double-basses. The strings provide accompaniment with the bow vibrato so beloved at the time for sensitive places - these four bars are repeated in the upper fifth by the violino piccolo, during which the woodwind and the strings exchange roles (the bow vibrato is now a "frémissement" on the wind instruments). The rewith the material which is to be developed is set out. Next, in a three-part sequence, the motif is first taken over the bass, while the strings and the woodwind play in stretto a kind of accompaniment motif; the solo oboe and the violino piccolo then take up the motif in stretto, and this is followed by a three-bar transition This sequence is repeated twice - one has the impression that it could go on forever - only to break off abruptly during second repeat at the bass motiv. The beginning of the stretto one was expecting here becomes an oboe cadenza, while the three-part bass - oboes - strings sequence is brought once more into prominence by alternating chords in the unexpected conclusion. The third movement is a true concerto movement with six rondo-like tutti blocks; the principal soloist is the violin piccolo, seconded by the first horn and the first oboe. The second tutti is somewhat remarkable in that it is played pianissimo: in movements of this kind one expects every tutti section to be forte; it is permeated by unusual oboe and violin solos. The fourth solo (violino piccolo and first ripieno violin) falls apart into an adagio chord, then is set going again by what seems to bc deployment of the rondo theme -the real tutti sections follow four bars later. Although this movement has the character of a finale, it is followed in turn by a minuet with the most varied trio combinations. It was quite customary at the beginning of the eighteenth century (eg. Handel’s concerti grossi) to conclude exciting or stormy concerti with a soothing minuet, in order to send the listener away in a relaxed frame of mind.
Brandenburg Concerto no. 2 shows a profuse rhetorical conception. It turns out to be a complex musical dialogue, in which inversions and other devices are used. Time afte rtime, there is an exchange of parts between the outer instruments. The instruments’ idiomatic language (the scoring of the solo quartet isextreme: a high natural trumpet, a recorder, an oboe, and a violin, almost a repertoire of the different ways of producing sound) achieves an impression of imitation by the transfer of specific instrumental figures to other instruments.
In the first movement there is a number of purely tutti motifs, and several others that are only played by the soloists. In that manner alone dialogue results. Bach failed to specify any dynamics, which shows that he expected the dynamic relations usual at the time: solo sections were played piano, tuttis as a rule forte. (This of course is quite the opposite ofpresent-day practice.) The soloist did not need to struggle against the tutti, as he was not accompanied by the body of the orchestra, but rather conducted a dialogue with them. The challenging initial statement from the tutti is succeeded by the protests of the solo instruments and the tutti reaction. It is important to note that in these various assertions the different parts are often simultaneously differently articulated. Sometimes this is expressly noted by Bach. Varying articulation in the different parts results in a more varied overall sound, with the characters of the individual instruments becoming more distinct. Bach obviously also expects differing articulation when a figure appears several times, since the figure then has an altered meaning in the rhetorical context. Analogy in the modern sense is non-existent in Baroque music, on account of its similarity to conversation.
The second movement has a double emotional personality, one side coming from the bass, the other from the solo instruments. The andante marking refers primarily to the bass, which proceeds in continuous quavers that are to be played at a steady pace. Bach sets this ostinato uniformity as a counterweight to the strong expressiveness of the three upper parts.
The third movement begins with a trumpet solo, which runs contrary to the tradition of the Baroque concerto movement and of Baroque rhetoric, for the statement that opens the movement is normally made by the tutti and then questioned by the solo. Here, the preceding movement leads directly into this solo, which is an answer to the last figure of the second movement; therefore there can be no pause between these two movements. The tutti just plays an orchestral continuo here: accompaniment, and the thematic events, are developed by the soloists and the bass alone. In terms of the concerto’s dramatic layout, that means that the entire finale is an enumerated acceptance of the challange of the first movement.
In the Brandenburg Concerto no. 4 the marking flauti d’echo poses something of a puzzle at first sight. High octave flutes were occasionally used, but these have much louder effect than ordinary recorders, so that the orchestra would then be the “echo”. Bach surely meant normal recorders. In the first rnovement the roles of the concertino are clearly given out to the group of soloists: the violin is the main soloist, seconded by the pair of recorders which are also brought to the fore again later in a lyrical solo section (bars l57-185 and 285-311). The echo effect in the second movement may have heen so important for Bach that he included it in the title of the concerto. The idea of the echo here is a rapid interruption of the melody, which would proceed continuously but for these echo insertions. The echos are at those points where one ought to write in a comma; they force one to listen attentively. The effect which Bach seems to have intended can only be achieved if the flutes are played from an adjoining room. At points where they are independent, as in bar 40, the orchestra must play more quietly to balance the sound. The andante marking of the second movement seems to refer to the tempo here, and not to an “andante” character of the whole movement. The slow movement should, then, receive a gradual acceleration; the paired quavers are not played steadily here. A fundamental feature of this movement is the perfect symmetrical arrangement, which is comparable with the architecture of a Baroque palace, and which Bach uses time and time again in his major works. Around a central section (bars 28-45) are grouped four outer sections. by way of framing: of these, the first and fifth only differ in the interchanging of the outer parts. The second and fourth sections correspond too, with the difference that the echoes in the 4th section have a compressed effect. In the central section there is new material and a new dialogue in that the recorders voice soloistic complaints here. In the fifth section the theme is in the hass, and the echoes of the symmetrically matching first section are omitted: they would not make sense in the repeat, since the effect would no longer be new. For interpretation it is most important to recognise this symmetry - one would play the piece difierently if the sections were just arranged in a row.
Although the third movement is to be played directly after the second, without a break, the recorder players have time to return to their places, since they do not come in until bar 23. In this movement the entire thematic material is derived from the first four bars.