Jun Senoue on Sonic Generations Original Soundtrack:

Trailer

The trailer that first appeared in this game was a depiction that both Sonics are about to run through after Classic Sonic joins in the running Sonic (Modern), but because we also wanted to convey the mystery contentwise without even showing the title yet, the music with the so-called trailerlike impression was prepared.

It had been arranged that we would also include the same clip in this game, but the concept varies for the recording of the unchanged music, which was appended to the aforementioned trailer that conceals the content as well as the title, so I turned out to prepare two compositions in one clip and use them separately. With the idea created when I first watched this clip, it is the decided composition that seems to apply the sound to the actions respectively. One might have also noticed that the melody is used as the result screen’s melody.