I think David I. has it right. Kawai built some with 2 or three extra strings in the bass with no action for them. Baldwin worked with the steel bar through the bass bridge extending out the back to "fool" the bridge into thinking it was longer. I assume the Bosendorfer extended scale may have the same effect. Mark Ritchie << I ran into the same thing and tossed it around my brain while tuning...decided it was there strictly to add more length to the bass bridge and another string under tension contacting it thereby letting avoiding the last actual sounding string to be at the end of the bridge...clear as mud? David I.>>
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