I was fascinated that one of the Secret Mathematicians discussed in Marcus du Sautoy's wonderful Gresham College / London Mathematical Society lecture a couple of weeks ago was Rudolf Laban. Some years ago a friend of mine was studying dance theatre at the Laban Centre (now part of Trinity Laban Conservatoire). She was studying hard for her exam on Labanotation, which is Laban's method of notating dance. I looked over her shoulder and was struck by the beautiful mathematics behind the notation. (Apparently this wasn't the right thing to say to somebody who needed to pass an exam in a subject with which she had no natural affinity - which I'm happy to say she did.)
Mathematicians tend to like good systems of notation, and notating something as fluid and instantaneous as dance is a huge challenge. I'm not qualified to say how effective Labanotation is for recording dance - my friend and her fellow dance students certainly didn't find it intuitive. But it has been used for one invaluable project.
Alec Finlay has notated Archie Gemmill's goal for Scotland against Holland in the 1978 World Cup. (You can buy the book from Amazon - I can't find a publishers' website.) That the notation which drive my dancer friend to distraction has been used to record the greatest goal ever scored in a football match is a demonstration of the importance of notation (which I regard as a branch of mathematics).