Speed, weight, and sounding point · From Zero to Mozart

Everything the right arm does to the sound comes down to three controls. Every violin teacher from Flesch to Galamian to Fischer names the same three, and every one of them says the same thing about them: they work together. Change one and you have to adjust at least one of the others, or the tone breaks.

The three controls

Bow speed — how fast the hair travels along the string, which is the same as how much bow you spend on a note. This is your volume control and your expression control. Faster bow → wider swing → louder.
Bow weight — how much of the arm's weight you let sink into the string (through a loose hand — you lean, you don't press). This is mostly a colour control: more weight makes the tone brighter and more focused, up to a limit. Past the limit it chokes.
Sounding point — where between the bridge and the fingerboard the hair meets the string. Near the bridge: bright, strong, but fussy. Near the fingerboard: soft, veiled, easy. (The next lesson, the-five-lanes, is all about this one.)

50 bpm

How to play it

Start slow and light in the middle lane. Each note: a bit more bow, a bit more arm weight, a bit nearer the bridge. Keep the sound clean the whole way — if it scratches, you moved one control too far ahead of the others.

Open A, growing from soft to loud over four half-notes. To do it you speed the bow up, lean a little more weight in, and drift a touch closer to the bridge — all three together. Try changing only one and hear how it fights you.

How they trade

A few rules you'll use constantly:

Nearer the bridge → the string is stiffer there, so it needs a slower bow and more weight to speak.
Faster bow → needs more weight to keep the string caught (or move toward the fingerboard, where less weight is fine).
The thick low strings (G, D) don't like the bow as close to the bridge as the thin E string does — their best sounding point sits a little further out.

Try it

Try

On the open D string, play a steady medium note. Now, keeping the bow speed and the weight exactly the same, slide the sounding point slowly from near the fingerboard toward the bridge. At some point it starts to scratch — that's the weight now being too little for that spot. Add a little weight and it clears up. You just felt the three controls trading.

The usual mistake

Trying to fix a bad sound by leaning on one control — usually weight. If the tone is rough, "press less" is only one of four fixes: you could also speed the bow up, move toward the bridge, or tilt the bow. Knowing they're a set means you always have options.