[hilbert42]

Stunningly useful even if you're a proficient pianist.

Moreover, Chang's a techie—an experienced scientist—so there's no bullshit or unnecessary padding here. As such, he'll appeal to many HN readers who tinkle the ivories from time to time and who'd like to improve their technique.

P.S.: I found his piano tuning info/techniques most interesting. As a hacker who couldn't leave well enough alone and who managed to put my old upright well out of wack and sounding like bar piano out of an old Western movie, this info would have been absolutely invaluable.