It's a shame someone has seen fit to give this only one star, just because their copy hasn't arrived. It's a shortish but authoritative listener's guide to all aspects of traditional pipe-music. It explodes some of the myths about its origins and traces the instrument's development; the emphasis is on ceol-mor, which is explained in a detailed but not-too-technical fashion, very useful for helping you understand just what is going on.
It's hard to think of anything more the book could offer - except that, because it was written before the recent revival in bellows-blown pipes, it doesn't have much to say about them or the current 'folk' scene. If you're into the Highland pipes in any remotely serious way, this is a must.