<html> <body> I've observed the same thing with my VT100.  Some pianos require as much as 1/2 cent sharp to end on pitch when you add unisons.  Some pianos don't go through a measure-able drop.  Now the VT is measuring a number of partials at once to calculate note placement so that may be why it shows up more readily with it. Andrew Anderson At 09:21 AM 6/14/2007, you wrote: <blockquote type=cite class=cite cite="">I would love a project that would result in a bringing together of the words we so loosely toss around and the concepts or postulates as I would call them. Hopefully after trying to define some of the concepts they become theorums that we can use to carry on decent discussions.   One another note. I was at the convention where Virgil Smith was going to show the difference between one string and the drop in pitch when adding the second string. Dr Sanderson was there to measure the difference and somehow I was lucky enough to be sittting right next to him.   So Virgil played the checks that aurally, everyone in the room could hear the difference. Then Dr Sanderson tried to measure it and there was no difference. He changed the note he was reading, moving up the partial chain and low and behold the note was flatter at the the 4th partial. At least I think it was the 4th, may be the 3rd. Certainly some ETDs will not focus on the proper partial so the operater has to override.   The change in the partial structure will certainly make a tuner alter his tuning and I think that is the point Virgil was trying to make.   Keith Roberts   On 6/13/07, Richard Moody <<a href="mailto:remoody@midstatesd.net">remoody@midstatesd.net</a> > wrote: <dl> <dd>I am thinking about a research project hopefully resulting in an article, to get interaction from piano technicians about  such concepts as, "coupled motion"  "para inharmonicity", "longitudinal vibration" (did you really understand that article in PTJ?), "reverse well", "well temperament", and why the 3 string unison is flat from the first string tuned. I forget what they call that but I have a tuning machine that shows it isn't true. </dl></blockquote></body> </html>