Detuning bass strings was Re: loose bridge pins

[Ron Nossaman]

>Hi,
>
>A couple of weeks ago someone asked if they could detune just the bass 
>strings, to work on the bass bridge, without damaging the frame. I was 
>surprised to read that one can! I have always been led to believe that you 
>have to detune the piano in a specific way eg. all A's, A#'s etc. I see 
>that Ron Nossaman has again ok'd the procedure, so I wasn't seeing things. 
>How is it that structurally the frame is able to withstand the release of 
>tension in the bass area? Is it related to the findings of Al Sanderson, 
>that the plate is "loaded up more equally" when pitch raising  starting on 
>A1 and going up chromatically?
>Thanks,
>
>Paul Tizzard

Hi Paul,
I don't have experience with tuning from A-0 up, but I do have a little in 
stringing. The bass strings go on after the tenor and treble strings are on 
and up to pitch, so you can seat and align everything in the tenor section 
before you cover them with the bass strings. Going the other way, I've 
never heard of any plate failures  from taking tension down in the bass 
(though anything's possible). That makes it statistically safer than a 
pitch raise. In fact, removing bass strings for bridge repairs has 
surprisingly little effect on the tuning of the tenor.

Ron N