<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"> <title></title> </head> <body bgcolor="#ffffff" text="#000000"> Well, I beg to differ. In fact, I know I am not even the slightest bit confused.  Tho perhaps we are talking a bit past each other here.  For the first, no one questions that string at lower tension... and I well suppose that means lower BPP as well will react more to a string length change then a string at a higher one.  I simply reacted to claims that you could calculate change in pitch directly from change in length.. which you still seem to hold on to.  You can not.  You are also incorrect as to the point on strings of same length, same pitch, but different diameter. They will indeed react identically pitchwise to the same amount of change in length. Run the numbers in that spreadsheet I posted and see for yourself.  I assume since you see this in terms of BPP you can look closer at the matter and find the reason from that perspective.  It is correct however that different length same pitch strings will change pitch differently for same change in length.  In any case... I still see nothing that you have posted that shows you calculating changes in pitches for changes in length... As for my spreadsheet needing a bit more work... it does exactly what it was meant to do... and if you find it lacking... please do take contact with Dr. Galembo and argue the points.  Or perhaps ask Askenfelt .  I am sure either will be more then willing to entertain your criticisms. Strikes me tho, that as a straight forward way of calculating pitch change for length change.... its quite easy indeed. A bit of easy standard trig, and Hooks law. And David... You started your last post with a plea to stay away from being antagonist.  I would ask you if you think your little ending statement in your second paragraph is in that spirit. Cheers RicB <blockquote> I believe you are the one confused.  Did you do the problem as I outlined? For BPP to change between two notes targeting the same frequency, the speaking lengths must be different.  To see whether a change in frequency between two strings will be different with a change in length as a function of BPP you must start with two strings that have a different BPP.  If the strings are equal speaking length then no matter how you change the string diameter altering the tension and hold the frequency constant, the BPPs will change together.  A change in length will not result in a difference in the change in frequency between the two.  However, if you start with two strings of unequal speaking length with the same starting frequency, the tension (a in the first example) will be different, but the BPP's will not be equal. Now when you impose a similar change in length there will be a difference in the change in frequency between the two.   The more complicated calculation comes because we comparing just two different notes on the same piano.  You then must do the calculations and convert the change on each note to cents deviation so that you can see whether as the percentage of a semitone, one changes more than the other. In other words, does the high bass go "out of tune" more or less than the low tenor.  The relative BPPs of the respective notes will give an indication of which will go out of tune more and it is the one with the lower BPP that will go out of tune more.  Namely, the BPP of the low tenor on a Steinway B, for example is around 22%.  The first note of the high bass is around 60%.   I have my own spreadsheet, thank you, perhaps yours needs a bit more work.   That's the best I can do with the explanation for now-I gotta go to woik.   David Love davidlovepianos at comcast.net <a class="moz-txt-link-abbreviated" href="http://www.davidlovepianos.com">www.davidlovepianos.com</a> </blockquote> </body> </html>