1. The operation of dividing voices undoubtedly weakens their resonance, and as the reader will have observed, one of the principal factors in good orchestration is equal balance of tone in the distribution of chords. But in choral writing the question is somewhat different. The orchestra, even after repeated rehearsal always plays from music; the operatic chorus, on the other hand, sings by heart. The chorus master can carry out the composer's instructions as to the division of parts in one way or another, varying and adjusting the number of singers to each part. By manipulating some shade of expression he can maintain a balance of tone between divided and undivided voices. In orchestral material the composer has to handle a great number of timbres, widely different in character and volume of tone. In the chorus there are but four qualities. A chorus moving about the stage cannot convey varying shades of expression so exactly as an orchestra seated at the desk. It may therefore be safely assumed that a composer is entitled to some licence in the question of dividing choral parts; dealing with the orchestra involves greater foresight and care.
2. In trying to obtain equal balance in writing three-part choruses for male or female chorus I have often resorted to the method of doubling the middle part as recommended on [p. 149]. The chorus master is at liberty to equalise the chorus by transferring voices from one part to another. In choruses divided into three parts I have noticed that chorus masters are in the habit of giving the upper part to Sopr. I, or Ten. I, and the two lower parts to Sopr. II and Ten. II divided. I consider this arrangement unsound, as the balance of parts can never be equal. The attention of chorus masters is called to the necessity of strengthening middle parts, for the expedient of giving prominence to the upper part concerns melody alone and leaves harmony out of the question.
3. Skilful management of choral parts is a fairly safe guarantee of clear and satisfactory performance. Miscalculations in writing are a great hindrance to study, and the most experienced chorus may come to grief through faulty progression of parts. If the progression of parts is correct, if discords are properly prepared, sudden and remote modulations, even of the harshest and most uncommon kind will be comparatively simple and may be approached with some degree of confidence. This is a fact which composers do not always bear in mind, but singers know it well and appreciate its importance to the full. As an instance I quote the very difficult modulation which occurs in [Ex. No. 169] (Sadko 302). I doubt whether it could be sung if written in any other way. Careful endeavour on the part of a composer is better than useless struggle inflicted upon the performer.
July 31st (Aug. 13th) 1905.
FOOTNOTES
[1] This manuscript was given to me by Alexander Glazounov; if a Rimsky-Korsakov museum is ever founded it will be placed there.
[2] This [preface] had already been published in his Notes and Articles on Music (St. Petersburgh, 1911).