I tend to teach this piece by rote and only show the notes once the tune is well learnt. Some teachers like to include movement in the rests, like 'windscreen wipers' for example. Others prefer that the players leave their bow on the string and relax their hold, getting used to not making sound while the bow rests on the string. In the improvisation sections I allow for optimum freedom, encouraging them to explore the instrument with no time constraints. I only insist on a good bow hold. Time limitations I introduce later once they have gained a little confidence. One approach is to suggest a musical 'conversation' with questions and answers. This helps to frame their improvisation into handy two bar phrases.
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