<HTML>The concept of adding another string, or strings, beyond A0, is to give more length bridge. That is the reason behind Bosendorfer's extra notes in the bass. Sure, it's impressive to have those added notes, but how many people actually play them?  From what I was told, by adding more notes to the bass, it pushed the last octave, A0 - A1, closer to the middle of the soundboard, where it could produce a bigger and more defined sound. Wim </HTML>