I have been struggling with the word gesture for a while. I, and many others in the music cognition/technology community, have been using it to denote music-related actions (i.e. physical body movement).
Not only is the term confusing in the musicology community (e.g. the way Hatten writes about inner-musical qualities), but it is also a misleading term in behavioral and linguistics communities, where gesture usually denotes communicative hand movement or facial expressions.
A couple of weeks back, Benoît Bardy mentioned that they never talk about gestures in kinesiology and biomechanics, only movement and action. He suggested that our “misuse” of the term might come from the large contingent of French researchers in our community, since the French geste is much less loaded than the English gesture. Thinking of it, in Norwegian I usually use the word bevegelse (movement) rather than gest when talking about gestures.
However, switching from gesture to something else isn’t that easy. I have been reluctant to using movement since this has such a strong connection to musical form and structure, and I am still confused about the difference between movement and motion. Goggle gives 201,000,000 hits for movement and 188,000,000 for motion, so they seem to even out. An English native speaker suggested that we can talk about movement of limbs, but motion in space. Thus movement is related to the body, and motion is related to a body in space. I will have to investigate that further. For the moment I think I will be going with movement for general usage, and action for denoting goal-directed movement, although it would be cool using motion since it works so well with emotion (e.g. music and (e)motion).