"Realization of the Art aims of the modern quartet calls for endless rehearsal. Few people realize the hard work and concentrated effort entailed. And there are always new problems to solve. After preparing a new score in advance, we meet and establish its general idea, its broad outlines in actual playing. And then, gradually, we fill in the details. Ordinarily we rehearse three hours a day, less during the concert season, of course; but always enough to keep absolutely in trim. And we vary our practice programs in order to keep mentally fresh as well as technically fit.
INTONATION
"Perfect intonation is a great problem—one practically unknown to the average amateur quartet player. Four players may each one of them be playing in tune, in pitch; yet their chords may not be truly in tune, because of the individual bias—a trifle sharp, a trifle flat—in interpreting pitch. This individual bias may be caused by the attraction existing between certain notes, by differences of register and timbre, or any number of other reasons—too many to recount. The true beauty of the quartet tone cannot be obtained unless there is an exact adjustment, a tempering of the individual pitch of each instrument, till perfect accordance exists. This is far more difficult and complicated than one might at first believe. For example, let us take one of the simplest violin chords," said Mr. Betti [and he rapidly set it down in pencil].
"Now let us begin by fixing the B so that it is perfectly in tune with the E, then without at all changing the B, take the interval D-B. You will see that the sixth will not be in tune. Repeat the experiment, inverting the notes: the result will still be the same. Try it yourself some time," added Mr. Betti with a smile, "and you will see. What is the reason? It is because the middle B has not been adjusted, tempered! Give the same notes to the first and second violins and the viola and you will have the same result. Then, when the 'cello is added, the problem is still more complicated, owing to the difference in timbre and register. Yet it is a problem which can be solved, and is solved in practically everything we play.
"Another difficulty, especially in the case of some of the very daring chords encountered in modern compositions, is the matter of balance between the individual notes. There are chords which only sound well if certain notes are thrown into relief; and others only if played very softly (almost as though they were overtones). To overcome such difficulties means a great deal of work, real musical instinct and, above all, great familiarity with the composer's harmonic processes. Yet with time and patience the true balance of tone can be obtained.
TEMPO
"All four individual players must be able to feel the tempo they are playing in the same way. I believe it was Mahler who once gave out a beat very distinctly—one, two, three—told his orchestra players to count the beat silently for twenty measures and then stop. As each felt the beat differently from the other, every one of them stopped at a different time. So tempo, just like intonation, must be 'tempered' by the four quartet players in order to secure perfect rhythmic inflection.
DYNAMICS
"Modern composers have wonderfully improved dynamic expression. Every little shade of meaning they make clear with great distinctness. The older composers, and occasionally a modern like Emanuel Moor, do not use expression marks. Moor says, 'If the performers really have something to put into my work the signs are not needed.' Yet this has its disadvantages. I once had an entirely unmarked Sonata by Sammartini. As most first movements in the sonatas of that composer are allegros I tried the beginning several times as an allegro, but it sounded radically wrong. Then, at last, it occurred to me to try it as a largo and, behold, it was beautiful!