William Strother writes:

>You must know that the 6th Piano Concerto is merely an adaption by
>Beeethoven of his Violin Concerto.  Of most interest to me is that he
>wrote out the cadenzas, and very unusual and interesting cadenzas at that.

There is another fragmentary Sixth Concerto, also in D major, the first
movement of which has appeared in a performing edition by Professor
Nicholas Cook.  I have only encountered it in MIDI format on the "Unheard
Beethoven" website:  http://www.unheardbeethoven.org/.  It's interesting
music, in a post-"Emperor" mode, and is definitely distinct from the Violin
Concerto.

DPHorn, who wishes that Beethoven hadn't put it aside.