Consignment 41 — Overstrung Upright, Temperament Octave

Sit that end of the bench. It's too low for me by a good two inches and I'm not shimming it today.

Here's the arithmetic before you touch anything. Twelve fifths up from A, perfect ones, four to one and a half, and you land back on an A about 23.5 cents sharp of where you began. That excess is fixed. It doesn't go away and it doesn't get argued with. Equal temperament is shaving a twelfth of it off every fifth — two cents a fifth — and that's the whole of it.

What you count is not a judgement. Two nearly-equal frequencies sounding together give you a loudness pulse at exactly the difference between them. Card says this fifth wants one and a half beats a second. One and a half a second. I count it against the pendulum — three beats in two swings. That's it. Not "sounds narrow." Narrow by that much.

Fifths set it, thirds check it. A tempered fifth in this octave beats slow, one to one and a half. A tempered major third beats seven or eight a second and you cannot mistake it for anything. Put a fifth two cents wrong and it barely shows; two steps later the third built on it is out by four a second and shouts. That's the reason for the order. Do them out of order and the checks tell you nothing.

Whoever carted this in stood it against the west wall in the sun all morning. Plate, wire and frame all expand at their own rates and it will not hold a single thing I do to it today. I'll say that again later when it's proved.

Middle C there is a replacement. Warehouse boy fitted the head in the spring out of a box of loose ones — sits half a millimetre proud and clicks on the fallboard coming back. Plays and tunes perfectly. Glue line will show for the life of it. Right — F♯.

Correction, first of three. I counted seven a second and read it off the fifth's line, which wants one and a half. The seven was the third I'd struck by mistake. Card's right, my finger was on the wrong row.

Octaves are tuned beatless and are still not simple. Steel wire is stiff. Its partials sit sharp of true multiples — inharmonicity — so the octave that beats nothing on the partials measures wide of a strict 2:1. That's the wire's diameter and its speaking length, and you cannot tune it out. Short cheap upright wants more stretch than a concert grand, which is why a temperament copied off one piano onto another is simply wrong.

The pin. It twists in the block before the wire moves, and the wire slips at the bearing points. Set it past and settle it back with a firm blow. Set it gently and you've set it high in the pin and it will be flat by Saturday.

Correction, second. Thermometer's up four degrees since one o'clock. A itself has moved under me. Re-strike the fork, re-check A, and everything I did before that is now a little off. Which — again — is that west wall.

Correction, third. I eased that one instead of striking it. It's sitting high in the pin. Do it again properly.

F♯ came in on the first pull. One blow instead of four. I'll take it.

Total raise across the whole instrument's about eleven cents, and every note I bring up pulls the plate and drops what's already done. So the temperament gets walked twice as a matter of course. Unisons come after, never before — outer strings stay wedged off with felt while I set this, because a unison out by half a beat makes every check unreadable. Felt strip lives in my teeth while both hands are busy.

One string in the B won't hold. I'll get it up twice more and then decide. Buyer's coming Saturday and the sun's still on that wall.