This was a useful resource that I found on kindle that taught me how to tune a piano for free. I was able to do that, despite some of this book's shortcomings. The free kindle version I had did not have the illustrations, which were frequently referenced and a rather important part of making the process clear. The content didn't really match up with the title, either, since much of the material was about learning the craft of being a piano tuner professionally, and extensive sections were made up of the mechanical workings of the piano and how to repair various issues that might come up (that, again, would have been greatly helped by the illustrations). A significant portion of the middle consisted of mathematical proofs that the tempered tuning that was taught was more effective than other versions, which was interesting, but not strictly necessary, and the portion on reed organ repairs was also unnecessary for me. This book also really showed its age, with instructions on how to make a pendulum to measure a second or instructions to get new hinges made by any local blacksmith. Of course, it is public domain, so that means it is an older book. It was effective in teaching me to tune a piano, though I did find myself wondering if there were more modern, simpler methods to tune pianos, so I had to take some time to look up alternatives outside of the book, but if you have the time, the price is right for learning an effective means of tuning a piano.