The whole instrument

The whole instrument
In this frame you direct your attention to your instrument as a whole. Acoustic instruments and voice all have resonating parts built in to them, which may not be in our thoughts when we play. Sometimes we are only focusing on the parts of our instrument that we touch or move when we play. Depressing the key on a grand piano also activates the back of the soundboard, under the piano. We have noticed that acknowledging this when playing can increase sound with little feeling of increase of muscular effort. By the same token, including the resonant back of the violin, viola, or cello in your idea of bowing, or picturing the whole column of the tube of brass or wood vibrating in winds and brass, can create the same affect. Singers know about the resonating cavities in the face, head and chest, but also often forget it themselves when working on a difficult piece, causing them also to force and work too hard.
Our body loves to move, and having the space to do so. Larger muscle groups will respond to create subtle movements also in response to the larger instrument picture in your mind. If your instrument is not acoustic, you can still think about the whole instrument when playing, which may have the same effects on your movements, freeing your playing.