Fortepianos and Schubertreise

For the series of thirty five recitals in Jodoigne (Belgium) Michel Stas and I are very fortunate in having a variety of period instruments at our disposal, provided by local piano maker Claude Kelecom. To date we have used a copy of a Walter instrument (1807) and an instrument attributed to Johann Schantz, made some time in the early 1820's (Both are featured on our video page on this site: http://www.thegreatschubertjourney.com/#!videos/c1cy9

It is fascinating to enter into the sound world of Schubert, quite literally — these were the sonorities that he grew up with (it is worthwhile reminding ourselves that he would have found the sonority of a modern Steinway instrument quite strange.) What are these differences?

A shorter keyboard, with smaller keys. For the clunky-fingered among us that takes getting used to.
A much more transparant bass register: there is far less steel used in a period instrument, and the tension on the strings is considerably less than in a modern counterpart)
A weak, thin-sounding treble register (which would explain the octave doublings in piano literature of the period)
A sound which dies away far more quickly than on a modern instrument (Barenboim's recording of Betthoven's Pathétique sonata in which he plays the opening Grave extremely slowly would not have been possible on a period instrument)
An una corda ('soft pedal') radically different from its milder modern cousin: a true change in colour. Schubert rarely calls for its use, but when he does, writing "Mit Verschiebung" at the beginning of Suleika I, the effect is startling
Knee-operated pedals (!) The system we know today was not in use at the time that Walter's instrument was built. A real-nonplusser for Michel Stas, who however copes very well with the challenge!
A tuning system strange to our modern ears. We are used to the tyranny of the modern equal- temperament system of tuning, in which each semitone is exactly the same distance from its neighbour. In older tuning systems, certain keys sounded out of tune, since to tune thirds and fifths accurately in say C major would mean that A flat major would sound slightly wonky. Personally I find it lends charm to music of this period, and, more importantly, the colours attributed to different keys make real sense. It is nonsense, as far as I am concerned, to talk of E flat major having a different colour than C major on a modern instrument: the only difference is geographical. (NB I have never come across a modern instrument not tuned to equal-temperament, and my suggestion to the National Concert Hall in Dublin that they retune the Steinway grand used in our series there met with a refusal (for practical reasons, which I understand.))