Weird track in SONIC ADVANCE

So I was play the Casino stage act one in SONIC ADVANCE on the SONIC ADVANCE SONIC BATTLE 2 in 1 pack, removed the cartridge an put it back. SUddenly, 4 oblong rectangles move in and this music playsCLICK HERE TO LISTEN.

I have only looked in the sound test and in OST's of both games. (I couldn't find it there, so the track may exist elsewhere?) E-mail me if you know!!