<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> <META content="MSHTML 6.00.2800.1106" name=GENERATOR></HEAD> <BODY> <DIV>My question would be: within the octave/s that you are experimenting with have you tuned all of the other notes? If so do the thirds, fourths, fifths, sixths fit nicely? If not then your stretch would need to be modified. The introduction of contiguous major thirds was a wonderful method of demonstrating just how much an octave would need to be stretched. If you are working on a spinet or a small poorly scaled piano there will be little chance of sorting this all out. </DIV> <DIV>Another idea here is: If you try to tune an octave as you progress up from the mid range and you tune to "minimize octave beating" as suggested, you may find that you have made the 2:1 partial quiet as this tends to have the most volume in this part of the piano. Then you will soon discover that your octave is too narrow.</DIV> <DIV>Gene Nelson</DIV> <DIV> </DIV> <DIV> </DIV> <DIV> -----Original Message----- From: D. B. Stang [mailto:stangdb@voyager.net] Sent: Tuesday, February 25, 2003 08:39 To: pianotech Subject: Stretch: What's it all about? </DIV> <BLOCKQUOTE>I am kind of a newbie, so if this topic is a dead horse that's already been beaten a few times, forgive me. What I would like to do is briefly describe my understanding of stretch and ask for comments about whether I am getting the idea or not. Randy Potter states the following: "We are simply trying to match our tuning to the amount of inharmonicity in the piano". (Randy Potter course book, section 1.6). "You do not put any stretch in the piano. The piano told you how much to stretch it. ... using 17ths and 3: and 4: octave tests, you would end up with a perfectly stretched piano". (section 1.7)  What he is saying is, minimize octave beating, and then a piano is stretched correctly. Well, recently I bought the Reyburn Cyber Tuner, which has a "Octave Tuning Style" feature, which gives the user a range of 9 levels of stretch you can choose from; "1" being "pure" (beat speed for the 4:2 octave at A2-A4 = 0), and "9" (beat speed = 0.8/sec.) I was immediately confused because this contradicts Potter, who says a piano is tuned "right" when octave beating is minimized, period. Meanwhile, I can remember a physics professor explaining that human hearing is "imperfect" because when we hear a pure octave, we think it's a little bit narrow, so pianos are stretched in order to make octaves sound more correct to the human ear. No one has ever explained all this to me succinctly. What I have concluded in my own little pea-brain is that there are two distinct kinds of stretch: what I will call "objective" and "subjective". The objective stretch is that which compensates for a piano's inharmonicity. The subjective stretch is the amount beyond the objective part, which makes it sound good to the listener. So when people use the word "stretch", they're not always talking about the same thing; sometimes they mean the objective part of it, sometimes they mean the subjective part of it, sometimes they mean both parts, and sometimes they don't know what they're talking about. Right ?? Any guidance on this subject is welcome.         </BLOCKQUOTE></BODY></HTML>