Show HN: Are you playing your violin (viola, guitar, etc.) in tune?
Note that the most natural way to sing or play a fretless instrument isn&#x27;t exactly 12 tone equal temperament. For example, if you play a major triad C-E-G as consonantly as possible, the frequency ratios C:E:G will be 4:5:6, which means 386 cents for C-E and 316 for E-G, instead of 400 and 300. The difference is quite audible. So be careful telling people they&#x27;re 15 cents sharp or flat, as it&#x27;s actually what makes the thirds and sixths in classical music sound so sweet!