Why is it called "Playing" when you make Music?

As I woke this morning, that is the question that was rolling about in my otherwise empty head. Most people would dismiss such a useless question as merely the result of indigestion from the prior evening's meal of greasy canned meat, but I could not so easily dispose of the thought. 

 
I don't suppose that it makes much of a difference, but, yes, the words we use are important. The denotative and connotative thought patterns associated with the word "play" are diminutive: 

engage in activity for enjoyment and recreation rather than a serious or practical purpose

For at least the last 2500 years, philosophers have considered music to be an essential element of being human. They have considered music to be a foundational cornerstone to education and life. Why, then, do we use the word "play" when we talk about making music?

It seems to me that music has a serious and very practical purpose: music allows us to communicate things that cannot be communicated in any other manner; Music allows each of us to expand our experience of who we are in a way that no other form of communication can; Music lifts our spirits and elevates our aspirations; Music allows us to think thoughts that are worth thinking!

Surely living a better life is a serious and practical purpose!