I am working on the reconstruction of Beethoven's 6th piano concerto (Hess 15). It will be published in 2016 in full orchestral scores.
To give you a first impression of the sketches one of my friends made a small clip. In the movie I give some examples how the pianoconcerto could sound, playing directly from the main autograph, Artaria 184, but also from the Mendelssohn 6 sketchbook. It's quite spontaneous, so please do not see it as something final.
At the moment I deciphre all Beethoven's notes, and each one of them will remain in place: one of my principles is not to change the Master's original. I am not only a musicologist but I am also a composer and think and feel as a composer. A musicologist does not empathize but argues from a musicological point of view. Being a composer is critical for an end result that is worth while to listen to. The piece is much more Beethovian and exciting than people may think when they listen to existing recordings.
In the sketches there is information for the cadenza and the development that I will use, it will have different voicing, etc. It will sound very different, more Beethoven notes, and perhaps also longer. I will use all the available sketches, I have just received the complete high res scans from the bibliotheca jagellonica from the 1 and 6 Mendelssohn sketchbooks. Last week I copied the disks to my computer. I already saw some great (new) material, even a new bagatelle and an unknown theme in B flat major (similar to the slow movement for strings in könig stephan or the adagio of the fifth piano concerto), but it is too early to tell whether there is enough material for additional slow movement.
Rectification/error: I say in the movie that alle works from 1811 have four horns, this is not correct. This must be 'almost all works', for example the 7th sympony (1812) is an exception.