Alfor,alfor wrote:If I remember correctly, Rubinstein himself mentions in his memoirs that it was him who added this glissando (I don't know whether he premiered the cycle, but he definitely was one of the first pianists to perform it).
Neither do I know, if Rubinstein ever published any of his own compositions, but he revised de Falla (reported by Harriet Cohen) and considerably thinned out the text of Albeniz' Iberia - which found the approval of the composer, who is reported to have done the same! And - reported by Darius Milhaud - he was able to play by heart (!) a lot of modern orchestral works on the piano!
I don't know what are your sources for what you wrote about Albeniz having approved a revised text of his Iberia by Rubinstein ... That seems quite uncertain to me, and I even doubt whether the young Rubinstein (21 years old when Albeniz finished his Iberia) could have known the original Iberia at that point. Albeniz died in 1909, shortly after completing his Iberia in 1908.
Regards.