Terry, Stretch is inevitable from all the test intervals, as you noted. The interval one chooses to use determines the stretch. Many tuners use a 6:3 octave in the bass, a 4:2 in the middle, tapering to a 2:1 in the treble. I went to a chapter meeting when I was much less experienced, and the RPTs were touting 10:5 and 12:6 octaves in the low bass, describing the more powerful sound they got. So, the next piano I tuned was an average American console for an elderly lady . I carefully went to 10:5 octaves in the second octave and 12:6 in the lowest. I got a call a few days later. She didn't like the bass. Actually, I didn't either, but my expert friends had said that it would sound good. Of course, they were not saying that this console needed that treatment. I re-tuned the bass back to 6:3 at the bottom, and the lady and I were happy with the result. I check out the lower 2 octaves by ghosting: depress A13 and A25 without letting the hammers strike. Then play A37, E44, and A 49 as moderately short forte staccato notes. You are setting up the tests for 4:2, 6:3, and 8:4. If these harmonic tones ring but don't beat, you are at 6:3. If you are closer to 4:2, the A49 will beat, so your A13 is sharp. If the A37 beats, you are flat with the lower note. If you are using the ETD all the way down, you look at the harmonics at the 4:2 note until you get to the last 2 octaves, then switch to the 6:3. You may find, as I have, that your ear is better and faster than the ETD. The piano truly will tell you where the best octave is. I am not saying that 6:3 always works in the bass, but it is the interval I use far more than any other. My take is that you don't add stretch beyond that which the tests tell you. However, with the variety of tastes we encounter, there must be those tuners and players out there who like more. John Ashcraft, RPT <div class="gmail_quote">On Fri, May 25, 2012 at 6:35 AM, tlneely <<a href="mailto:tlneely@mindspring.com" target="_blank">tlneely@mindspring.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Hi all, As we all know, when tuning up and down from the temperament, octaves are stretched from the theoretical pitch of pure octaves as one might find on a pipe organ due to the piano being an inharmonic instrument. We determine this expansion based upon test intervals and "let the piano tell us" how much it should be. For years at conferences I have heard respected folks discuss that you have to "stretch the octaves". Everyone nods their heads wisely, and the discussion moves on. My question is this- Is the stretch being discussed in addition to that indicated by the tests? Should one do this. If so why and how much? I suppose I should confess here that I learned to tune aurally on harpsichords and fortepianos where the inharmonicity is much less than in the piano (using equal beating historical temperaments). I use an ETD for piano work(have owned most all of them over the years). Thanks, Terry Neely </blockquote></div>