standard tuning
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------------------------------------------777----
-x-x-x-3-----x-x-x-5-----x-x-x-7----x-x999777----
-x-x-x-3-----x-x-x-5-----x-x-x-7----x-x999555----
-x-x-x-1-----x-x-x-3-----x-x-x-5----x-x777-------
repeat this part three times
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-9-9-xx-7-7-xx-5-5-xx-333555-------------------------------------
-9-9-xx-7-7-xx-5-5-xx-333555------------------------------------
-7-7-xx-5-5-xx-3-3-xx-111333-----------------------------------
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