Giuseppe Tartini is one of the best known violinists of the baroque - yet his reputation today rests on a surprisingly small proportion of his output - his L'Arte dell'arco, variations on a Corelli gavotte, and his Devil's Trill sonata. He was a prolific composer (almost exclusively for violin), and increasingly a somewhat esoteric theorist. He was also extremely well known as a teacher - and for the performance practice movement his 1771 Regole per ben suonar il Violino and this letter hold enormous importance.
Apparently written in place of a long promised but never given lesson, the letter starts with an extremely valuable description of mid-18th century bowing practice. One can do little better than let Tartini speak for himself;
"Your principal practice and study should, at present, be confined to the use and power of the bow, in order to make yourself entirely mistress in the execution and expression of whatever can be played or sung, within the compass and ability of your instrument. Your first study, therefore, should be the true manner of holding, balancing and pressing the bow lightly, but steadily, upon the strings; in such manner as that it shall seem to breathe the first tone it gives, which must proceed from the friction of the string, and not from percussion, as by a blow given with a hammer upon it. This depends on laying the bow lightly upon the strings, at the first contact, and on gently pressing it afterwards; which, if done gradually, can scarce have too much force given to it, because, if the tone is begun with delicacy, there is little danger of rendering it afterwards either course or harsh.
Of this first contact, and delicate manner of beginning a tone, you should make yourself a perfect mistress in every situation and part of the bow, as well in the middle as in the extremities; and in moving it up, as well as in drawing it down. To unite all these laborious particulars into one lesson, my advice is, that you first exercise yourself in a swell upon an open string; for example, upon the second or a-la-mi-re
: that you begin pianissimo
, and increase the tone by slow degrees to its fortissimo
; and this study should be equally made with the motion of the bow up, and down, in which exercise you should spend at least an hour every day, though at different times, a little in the morning, and a little in the evening; having constantly in mind, that this practice is, of all others, the most difficult, and the most essential to playing well on the violin. When you are a perfect mistress of this part of a good performer, a swell will be very easy to you; beginning with the most minute softness, encreasing the tone to its loudest degree, and diminishing it to the same point of softness with which you began, and all this in the same stroke of the bow. Every degree of pressure upon the string, which the expression of a note or passage shall require, will by this means be easy and certain; and you will be able to execute with your bow whatever you please. After this, in order to acquire that light pulsation and play of the wrist, from whence velocity in bowing arises, it will be best for you to practise, every day, one of the allegros
, of which there are three, in Corelli's solos, which entirely moves in semiquavers. The first is in D, in playing which you should accelerate the motion a little each time, till you arrive at the greatest degree of swiftness possible: but two precautions are necessary in this exercise; the first is, that you play the notes staccato
, that is, separate and detached, with a little space between every two: for though they are written thus,
they should be played as if there was a rest after every note, in this manner
The second precaution is, that you first play with the point of the bow; and when that becomes easy to you, that you use that part of it which is between the point and the middle; and when you are likewise mistress of this part of the bow, that you practise in the same manner with the middle of the bow; and above all, you must remember in these studies to begin the allegros
or flights sometimes with an up-bow, and sometimes with a down-bow, carefully avoiding the habit of constantly practising one way. In order to acquire a greater facility of executing swift passages in a light and neat manner, it will be of great use if you accustom yourself to skip over a string between two quick notes in divisions, like these,
Of such divisions you may play extempore as many as you please, and in every key, which will be both useful and necessary."