<html> <body> Phillippe, I am not sure what you mean by a "stretched temperament."  Tuning is stretched on a piano because of inharmonicity caused by the stiffness of piano wire.  When the wire subdivides vibrations after being struck by the hammer it does so losing a little length with each subdivision because the wire is stiff.  The higher the partial, the more length is lost and the sharper the coincident tone.  When tuning a piano aurally, stretch occurs naturally as you match those partials.  You hear the tone blossom or open up, if you will, as you come into coincidence.  Where you place it in that narrow zone is a matter of taste--narrow, middle or wide. Because different pianos are scaled (choice of wire size) differently, no one recording of reference tones will work throughout the compass.  Sometimes manufacturers will "refine" their scaling in a given model more than once in a year and the same model of piano will actually have a different scale.  The result of different scales is different tuning sometimes obvious at the extreme ends of the compass.  The pianos will not harmonize to a greater or lessor degree.  Actually, a lot of scaling refinement happens at the break from the long bridge to the bass bridge and the break from wound strings to unwound strings.  An example of how scaling differences can show up in real life happened at a university where my wife worked as a pianist.  They had a NY Steinway D and a Bosendorfer concert grand.  For a concert they chose to have four-hand, two piano accompaniment of the mass choir.  I was attending the concert and during an intermission the choral director approached me and asked/complained why their tuner couldn't get the pianos in tune with each other.  Knowing the person in question was a fine, pre-eminent technician, I knew the problem wasn't the tuning and asked about the pianos.  I explained how different piano makers would scale their instruments differently pursuing different philosophies of sound and that in order for a piano to be "in-tune" the resulting scales must be tuned differently.  The only perfectly harmonious note she could count on would be A4, middle A.  (Even then such different pianos would respond to climate differently and go out of tune differently.)  Steinway with its low tension scale and Bosendorfer with its high tension scale were destined to clash.  Those piano-makers have very different goals they accomplish with their instruments.  The university has since purchased another Steinway D. This is why guitar tuners do not work for tuning pianos.  Piano tuners are more complex and cost multiples of an ordinary tuner.  There are a variety of electronic tuners offered explicitly for tuning pianos.  The cheap ones have stretch templates that may or may not do a good job of "parodying" the piano you are tuning.  The mid-level ones sample three notes on a piano and then calculate a stretch curve for the entire piano.  The high-end one measures each note you tune and fits it into the scale based on the measurements and records those measurements along with partial strength to influence the placement of other notes.  Scaling breaks occur at many places in the piano.  Every time you change wire size, you have a scaling break.  That will influence tuning.  People who tune relying strictly on their ETD will find that aural checks of an FAC type ETD will reveal tuning problems on pianos that have prominent scaling breaks (usual in little pianos). As to temperament preferences, Equal Temperament is the most dissonant temperament.  It is also the most flexible temperament, allowing transposition without changing the character of a musical piece.  The further you wander from equal towards just temperament the more consonant common keys and intervals will become.  This comes at a price.  The dissonance will be confined more and more into increasingly dissonant keys/intervals.  The repertoire becomes more and more constrained by the tuning.  I like well-temperaments.  I've enjoyed Barnes Bach on a piano for some time.  The piano sounded much better and more powerful as many intervals were close to consonant.  The difficulty was in the more modern repertoire.  Debussy came across more like sand-paper then the creamy/dreamy sounds you expect from this composer.  Composers that utilized unequal temperaments wrote pieces that took advantage of those inequalities.  When you switch keys in Mozart, Beethovan, Bach etc. you audibly switch gears in a well-temperament.  Modern composers wrote for what they heard on the piano, some advocated for ET.  Understand what you are getting when you choose a tuning and then make your choice. Good luck, Andrew Anderson At 06:30 AM 2/12/2006, you wrote: <blockquote type=cite class=cite cite="">Hi all,   I'm currently studying temperaments, and I wonder if a tuner always use a stretched temperament, especially since this doesn't seems quite compatible with the use of electronic tuning devices. (for the not aural tuners...)   This question, especially since I've a CD with reference tones for a stretched temperament, which seems quite strange since a stretched temperament should depend on the kind of piano, shouldn't they ? So what ?   subsidiary question : as a tuner, do you prefer to use equal temperament ? or do you prefer to use another one ? (which one) ... Or do your clients often have their specific requests ? (in this case what are you commonly asked ?)   Philippe Errembault</blockquote></body> </html>