[CAUT] Case of the mysteriously breaking treble strings

[Jeff Olson]

Speaking of UFOs, I was having trouble identifying the cause for a 
stubbornly breaking treble string in the high treble of an older upright.

It began with one string that broke twice.  The first time, I assumed I'd 
nicked it or something installation.  The second time, I wondered if it was 
hanging up on something.  But I'd cleaned and polished the pressure bar, and 
I didn't spot anything abrasive on the bridge or harp.

Then, as I started chipping the piano to pitch, several more strings broke 
in the high treble (#13).  I decided to measure the wire, though it was 
coming fresh out of a new packet (Roslau), and was surprised that the 
labeled 13 was actually 13 1/2.  That seemed odd, but not likely to explain 
the breakage.  In any case, I switched to 13 -- actually micced it this 
time -- and the strings still broke.

Then, finally, I figured it out.  Any ideas about what the "mystery cause" 
was?

Best,

JeffO