I'm not challenging this statement, as I noticed it pretty quickly myself after I synced the
Skyward Sword soundtrack to my iPod. But, I would like to point out that Demise's themes seem to contain many songs from prior titles. Check out this one, that I picked out from the 'Battlefield of Demise' theme:
Battlefield of Demise @ 1:21
Raining Theme from the beginning of A Link to the Past
There's something there. Definitely. Actually, it took me a little while to figure out which tune that was--though I knew for sure it was from
A Link to the Past. I figure it's foreshadowing, right? Ganon's Theme... this theme... and most-likely a few others. I automatically associate that raining theme [which somewhat has the melody of Ganon's theme] to the Imprisoning War, because of the intro of
A Link to the Past, so... it's hinting The Imprisoned? No way...
Probably a little easter egg thrown in by the wonderful composers of the
Skyward Sword soundtrack. As Zelda fans, we know these tunes, so when we hear them hidden within other songs, it makes the connection easier for us to make.