---------------------- multipart/alternative attachment "I strike the F below the A and listen to the fork A along with the F. I count those beats. Then I remove the fork and play the F and the A and count those beats. " I don't know if the writer really meant literally "the F below the A", but I also saw a reference in another post to a "F2-A3" comparison with the fork, so I just wanted to make it clear that although F2, F3, and F4 will all beat against A4, only the F2 [2 8ves + M3rd] will give an accurate comparison between an A4 fork and the A4 note on the piano. Here's why: The 5th partial of F2 is approximately equal to the fundamental of A4. In a tuned piano, it will be about 4 beats flat of both the fork and the note, but it can be set anywhere comfortable. I like 5 or 6 beats even better. When A4 on the piano is in tune with an A4 fork, the beat of either against the F2 beat-producer note will be the same. This is such a great method because, even as the notes become in tune, the beats remain in a comfortable range [4 to 6/sec] in which the ear is amazingly adept at comparison. On the other hand, in trying to match a note directly to a fork, the closer the match, the slower the beat. And, it never becomes completely clean, because of beating between harmonics of the source and "inharmonics" of the piano. Just last Saturday, our Chapter set an A as a group by the F2-A4 method, and were very quickly able to agree on a setting which we then measured electronically as being only 0.2 cents off. That's not bad. By the way, we used an AccuFork. We had a grand with a sostenuto, which you can use to hold down the F2, but I also demonstrated playing it and jamming a mute between it and F# to hold it down, then tuning the A4. The 5th partial of ~F3~ on the other hand, is ~A5~, which matches the desired A4 at its SECOND partial, A5 [a 5:2 match]. The A5 produced by the fork is harmonic, but that produced by the piano is a little sharp. Matching this coincidence causes the piano's A4 to be slightly flat. F4-A4 [a 5:4 match, coincident at A6] would produce an even flatter A4, with equal beats between the fork and piano. I hope that's clear. We're probably all on the same page, but I just wanted to make sure everyone out there knows why only F2 works accurately. Bob Davis ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/3f/9f/a4/d9/attachment.htm ---------------------- multipart/alternative attachment--
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