The Granados isn't really a reconstruction at all, but an invention. From Hyperion's website:
Like Albéniz, Enrique Granados (1867–1916) was a brilliant pianist (he studied with Charles de Bériot in Paris) and a composition pupil of Felipe Pedrell. Both are best remembered as composers of overtly Spanish piano cycles (Albéniz's Iberia and Granados's Goyescas), but both also wrote extensively in other forms, including opera, a form in which Pedrell was also active. The Centre de Documentació Musical de Catalunya in Barcelona has two tantalizing fragments of a piano concerto by Granados which Melani Mestre has taken as the point of departure for a finished work. The first of the Barcelona manuscripts is a two-piano sketch in Granados's hand, with a dedication 'à mon cher maître Camille Saint-Saëns', and the subtitle 'Patético'. Though this manuscript has no date, Melani Mestre has suggested that it was written in 1910, around the time Granados was at work on Goyescas.
The sketch opens with a long, brooding piano solo, and the tempo changes to Allegro grave non molto lento when the orchestra makes its first entry. Altogether there are some 250 bars of music in this sketch, which breaks off in the middle of a bar. A second autograph manuscript is much neater, but the opening solo, marked Lento grave e quasi recitativo, is considerably shorter (just eighteen bars—less than a quarter of the length of this solo in the sketch), before the initial fully scored orchestral entry. This manuscript has several blank pages between orchestral entries where Granados may have intended to add the solo part, and it ends with nine pages of full orchestral score before stopping abruptly.
Musicologists will never agree about the viability of completing a work that exists only in a fragmentary state, and for which there is no surviving continuity draft to indicate what Granados's intentions might have been for the entire movement. Putting those questions to one side, what Mestre's completion demonstrates is that the surviving sources provide ample material for a single movement of considerable interest. The music is unusually dark and sombre, centred on C minor (the key of Beethoven's 'Pathétique' Sonata, presumably no accident given the subtitle 'Patético' on the sketch), and Granados can be heard here at his most gravely expressive and harmonically resourceful. It is unclear whether he set out to write a three-movement concerto (there is some evidence that he did), or whether he thought that this substantial single movement could stand on its own. Mestre believes that Granados had a three-movement work in mind, and to create that (since there is only material for the first movement in the Barcelona manuscripts) he has taken two solo piano works, orchestrating and adapting them for piano and orchestra. The second movement is based on two pieces: Oriental, No 2 of the twelve Danzas españolas, and Capricho español. The finale is an arrangement of the Allegro di concierto.
(emphasis added)
Like Albéniz, Enrique Granados (1867–1916) was a brilliant pianist (he studied with Charles de Bériot in Paris) and a composition pupil of Felipe Pedrell. Both are best remembered as composers of overtly Spanish piano cycles (Albéniz's Iberia and Granados's Goyescas), but both also wrote extensively in other forms, including opera, a form in which Pedrell was also active. The Centre de Documentació Musical de Catalunya in Barcelona has two tantalizing fragments of a piano concerto by Granados which Melani Mestre has taken as the point of departure for a finished work. The first of the Barcelona manuscripts is a two-piano sketch in Granados's hand, with a dedication 'à mon cher maître Camille Saint-Saëns', and the subtitle 'Patético'. Though this manuscript has no date, Melani Mestre has suggested that it was written in 1910, around the time Granados was at work on Goyescas.
The sketch opens with a long, brooding piano solo, and the tempo changes to Allegro grave non molto lento when the orchestra makes its first entry. Altogether there are some 250 bars of music in this sketch, which breaks off in the middle of a bar. A second autograph manuscript is much neater, but the opening solo, marked Lento grave e quasi recitativo, is considerably shorter (just eighteen bars—less than a quarter of the length of this solo in the sketch), before the initial fully scored orchestral entry. This manuscript has several blank pages between orchestral entries where Granados may have intended to add the solo part, and it ends with nine pages of full orchestral score before stopping abruptly.
Musicologists will never agree about the viability of completing a work that exists only in a fragmentary state, and for which there is no surviving continuity draft to indicate what Granados's intentions might have been for the entire movement. Putting those questions to one side, what Mestre's completion demonstrates is that the surviving sources provide ample material for a single movement of considerable interest. The music is unusually dark and sombre, centred on C minor (the key of Beethoven's 'Pathétique' Sonata, presumably no accident given the subtitle 'Patético' on the sketch), and Granados can be heard here at his most gravely expressive and harmonically resourceful. It is unclear whether he set out to write a three-movement concerto (there is some evidence that he did), or whether he thought that this substantial single movement could stand on its own. Mestre believes that Granados had a three-movement work in mind, and to create that (since there is only material for the first movement in the Barcelona manuscripts) he has taken two solo piano works, orchestrating and adapting them for piano and orchestra. The second movement is based on two pieces: Oriental, No 2 of the twelve Danzas españolas, and Capricho español. The finale is an arrangement of the Allegro di concierto.
(emphasis added)
