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In this video I go over the basics about playing double stops on the violin. I tell you the different difficulties and where you should start.
I can highly recommend you the Etude Book by Enrico Polo, which I show you in the video. It has many different etudes from more basic to very advanced.
But remember that double stops are an advanced technique already and need good intonation. But also you can make your intonation much better when practicing double stops with open strings.
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