<html> <body> ><br> <pre>You tune to normal equal temperament, but when you tune the unisons you >raise the right string by 6 Hz (beats) and lower the left string by 6 Hz. >This is starting at A440.... A220 the right string should be 3 beats up >and the left string 3 beats down... by A880 the right string will be tuned >12 beats sharp and the left string 12 beats flat, and so on. This should be fairly easy with an ETD. Tune all middle strings at pitch. Then set the ETD to +6 Hz and tune all right strings, set to -6 Hz and tune all left strings, or vise versa. Or so it seems to me. <x-sigsep><p></x-sigsep> Regards, Jon Page, piano technician Harwich Port, Cape Cod, Mass. <a href="mailto:jonpage@comcast.net" eudora="autourl">mailto:jonpage@comcast.net </a>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ </body> </html>