Jun Senoue on Sonic Generations Original Soundtrack:

Sky Sanctuary

As with Green Hill, the atmosphere of the original music is relative comfortable and we produced the two-phase versions separately for the modern style in this stage in order to also be the stage structure, which is different from the tempo feeling of the original. I think it could show the unusual, natural atmosphere like the lush greenery in a place floating on the vast sky and in which we can feel the expanse.