A great example of how to describe embodied knowledge and self-observation as well as a document of how hard it is to do, particularly in text. I think, it would like to be a 3 hour youtube video essay (A format not around at the time of writing).

If I remember correctly, it is also praised to ethnomethodologists as serving both as document and instruction. I would be surprised if many ethnomethodologists actually tested this claim and tried to become uniquely adequate jazz pianists by using this book, though I think it can certainly help a learner (particularly one that is interested in Ethnomethodology!)