Why does the author define music as 'a very small word'?

Question

Why does the author define music as 'a very small word' even though it encompasses something that takes as many forms as there are cultural or subcultural identities?

‘Music’ is a very small word to encompass something that takes as many forms as there are cultural or subcultural identities. And like all small words, it brings a danger with it. When we speak of ‘music’, we are easily led to believe that there is something that corresponds to that word—something out there, so to speak, just waiting for us to give it a name. But when we speak of music we are really talking about a multiplicity of activities and experiences. It is only the fact that we call them all ‘music’ that makes it seem obvious that they belong together. There are cultures which don’t have a word for ‘music’ in the way that English does—so that music isn’t distinguished from what we would call dance or theater.

Music: A Very Short Introduction

Answer 1

He means that music is a short word (5 letters) for a very wide range of human activity, and warning us not to think that just because there is a simple word, that the activity that it refers to is simple.

He further notes that in some languages the category of "music" is different from English. In some languages, what we call "dance" is just a type of music.

Answer 2

I think the author wishes to emphasise that our understanding of a simple word like 'music' can be too vague, because 'music' refers to a complexity of activities and experiences. If I were the author though, I would not have used small to describe the word 'music'.

Edit: I would put maybe 'little', I prefer it to 'small' in written language. 'Simple' is not bad either. But I think that maybe common was the actual intended meaning here.