Bow Elbow Level
Start by placing the bow on E string. Bow is on E string, Elbow is on E string. Elbow is relaxed, close to the body. The bow arm wrist is flat. The bow knuckles are flat.
When playing on E string, be sure bow elbow remains on E string at all times. In Book I, we master E string elbow, then we begin to play on A string too. In the first half of the book, our playing is limited to E and A strings. When we play on A string, the bow elbow should remain on E string level. So, bow elbow remains one level lower than the bow for A string. It is the same when you move to D string and G string. The arm/ elbow will rise to A string, when you play on D string. It will rise to D string to play on G string.
Bow on A string; elbow on E. When your piece involves only E and A strings, leave the elbow on E string level and lift the hand only for A string notes.
When you play on D string, raise the hand from A string level elbow position. Always just raise the hand if you only need to play a note or two on D. But if the passage requires G string and most of the notes are on D, you will need to allow the bow elbow to be centered at the D string level. In all cases, keep the elbow under the bow hand. Keep the elbow relaxed and the wrist flat.
In Book I, maintain E string elbow, played in the upper half of the bow, until Etude. Then, bring the level of the elbow slightly higher to play on G and D. Return to E string elbow position when playing on A and E string. Raise only the hand if you only need to play a few notes on lower strings, while keeping the elbow in a lowered relaxed position.
Dr. Suzuki states the purpose for keeping the elbow in a lower position allows for the weight of the arm to be used to produce open, ringing tone by ‘pulling’ the bow. When the arm is above the stick of the bow (and in some schools of thought, it is) there is a tendency to increased tiredness and pressure that disrupts beautiful tone.