In the performance of the St. John Passion recorded on this disc, we have attempted to realize Bach's wishes and conceptions in the most authentic manner possible. In doing so, we have started with the conviction, confirmed by many investigations, that every age possessed the optimum possibilities for the performance of its music. The objection is often raised that instruments and their techniques have been so much improved and further developed in recent times that it would be a retrograde step to return to the old instruments today, also that the small numbers of performers at that time were only an emergency solution; they would have preferred performing with the usual large groups of today at that time too, if only they had been able. Regarding the technical development of the instruments: each "improvement" to an instrument has to be paid for with new disadvantages. For instance, the introduction of keys for the semitones on the flute was resisted for many decades. The improbement (easier "speaking" and uniformity in sound of all semitones) would not compensate, for the taste of that time, for the disadvantages it involved (the variety of tone-colours of the semitones produced with forked fingerings was lost, and with it particular characteristics of key). The instrument was first altered when musical style had changed so that this variety of tone-colours was no more desired. We should consider the "improvements" to which all instruments have been subject in the course of time as changes, as adaptations to the taste of the age. It thus becomes clear what is meant when we say that every age possessed the best instrumental resources for the performance of its music. The same applies to the numbers of performers: there is old music written for large and for small groups. The composers of those days regarded it as their self-understood task to adapt their works as well as possible to the possibilities of performance at their disposal, both in view of the members available and the acoustical circumstances. They never composed for any ideal performances in future times. Bach certainly did not have our gigantic performances of his Passions in mind. The monumental character of these works does not lie by any means in the size of the sound-producing masses, but in the substance of the music iteself. Any change in the original relationships can cause a distorsion of the balance. It is thus absolutely necessary, within the framework of a performance with a boys' choir and with instruments of Bach's time, that the soprano and alto solos are also sung by boys. The question is always raised in this connection whether children can provide the necessary musical qualities for the interpretation of such demanding works. A Thirteen-year-old boy cannot, to be sure, compete with the musical knowledge of an experienced woman singer; he will approach his task with a much more natural, naive attitude. Given the appropriate talent and guidance, boys are fully capable of "understanding" this music and performing it with the utmost dedication. Too much so-called expression, as can so easily arise with operatically trained women singers, spoiling the balanced concerted performance with the solo instruments, need never be feared. The special timbreof boy's voices just cannot be replaced.
We have today reached the stage where we accept the music just as it was written; fidelity to the work is a recognized demand (fifty years ago people still believed old music could only be presented in re-arranged versions). The sound-producing components cannot be excluded indefinitely from these endeavours. This usually happens in the belief that one cannot expect the listener to accustom himself to a new (the old) sound-picture, to another dynamic scale. The fact is that the public has already become accustomed to the music iteself, which is just as remote for us in time, althoug formerly nobody wanted to believe this would happen. One day we shall have to recognize the fact that the wish to hear old music in an unedited form, as close to the original as possible, sets off a chain reaction  (tempi - numbers of performers - acoustics of halls - sound and sound-blending of the instruments), which cannot be halted, and at the end of which stands a performance corresponding to the circumstances of the time of composition in ebery respect.
The highly characteristic, sharp and clearly defined sounds of the old instruments, the voices of the choir of boys and youth all became blended and bound together in the resonant acoustics of baroque halls and churches. It is a clarity without hardness, without over-sharpness of detail, in other words not merely a full score in sound. This uncompromising striving for the original is, of course, only justified when the most important thing of all is also present: glowing vitality and full commitment in the music-making, for music has never been performed objectively and impersonally - least of all in the case of Bach.