I broadly agree with the replies above except that for me the fastest, shortest notes (eg, fast 16th note passages) happen best on-the-string near the balance point of the bow regardless of the dynamics. Bow quality, stick strength and hair tension will all influence where you play certain strokes. Each stroke has its own best speed range. The one stroke that has no limits either way is on-the string.
The following are the most general of suggestions -
- conserve the rosin on first 3 inches at the frog for the heaviest, least musical attack during performances (this was Tom Martin's suggestion)
- the "comfort zone" of the bow length is from just inside the balance point out to about half way (where the hair bends more and grips the strings, you can start notes of any length and style easily and the sound is more musical than at the heel)
- string crossings are easiest at or very near the balance point because there is the least amount of physical effort - the bow is "in neutral" and does not fight you, and the arc of hand movement is almost minimized)
- on the string, off the string and semi-off bow strokes each present different challenges (here is where a really good bow, one that works well throughout its length in each direction, helps a lot)
- the carried, flatter bounce or brush stroke, (eg Haydn/Mozart)) happens best around the balance point
- the heavier, louder off-string bounce (i call it gouging) is best closer to the frog, inside the balance point, where the weight of the bow helps you dig into the string more vertically
- the lighter sounding ,faster "Italian" spiccato is produced closer to the middle of the bow, where the bow tracks more vertically in a vee shaped bounce (a struck stroke vs a carried scoop). Each individual bow has its own sweet spot for this stroke.
- spiccato needs some speed for comfort and gradually becomes sautille then finally back on-the string as notes get faster.
A useful on-the-string bowing exercise is to begin long slow bows on one note with no release at each end. Do not try to push the bow through the change of direction - very simply change direction and feel the bow neatly grab the string in a musical way without any accent. Then keep the bow weight, volume and sound quality as constants as you gradually speed up the tempo, shortening the bow length and contracting movements towards the balance point. The bow length becomes directly proportional to the note length. Too much bow will skid and too little will grunt. In between there is a window of lengths that potentially give you clear articulation with a musical sound over a wide range of volume. Then broaden out the movements as you slow down (the reverse process). You can easily contract to and expand from any given point of the bow length.