Visualising a boat sailing across calm waters is one way to encourage a relaxed and gentle bowing action when playing this piece. I prefer to teach it by rote allowing the pupils to focus all their attention on their bowing. Visualising the bow itself as a boat, travelling from one end to the other is also helpful. Simple swaying, left to right makes for good visuals from the audience's perspective as well as helping to relax the bow arm. I also ask them to play louder in the Da Capo.
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