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When you opened the file in the music app, pressing the 'play/pause' button with right mouse click (or click for a few seconds on the play icon) opens an extra menu where you can set the desired playback speed:
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When you opened the file in the music app, pressing the 'play/pause' button with right mouse click (or click for a few seconds on the play icon) opens an extra menu where you can set the desired playback speed:
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