In the course of a shift in low positions, the thumb of the left hand moves up or down the neck of the instrument so as to remain in the same position relative to the fingers (though the movement of the thumb may occur slightly before, or slightly after, the movement of the fingers). In such positions, the thumb is often thought of as an 'anchor' whose location defines what position the player is in. In very high positions, the thumb is unable to move with the fingers as the body of the instrument gets in the way. Instead, the thumb works around the neck of the instrument to sit at the point at which the neck meets the right bout of the body, and remains there while the fingers move between the high positions.
In the course of a shift in low positions the thumb of the left hand moves up or down the neck of the instrument so as to remain in the same position relative to the fingers (though the movement of the thumb may occur slightly before or slightly after the movement of the fingers) In such positions the thumb is often thought of as an 'anchor' whose location defines what position the player is in In very high positions the thumb is unable to move with the fingers as the body of the instrument gets in the way Instead the thumb works around the neck of the instrument to sit at the point at which the neck meets the right bout of the body and remains there while the fingers move between the high positions