I always found it strange how Arecus always has such creepy and foreboding themes associated with Him. Unlike the older Shin Megami Tensei games, the creator figure of Pokemon is portrayed as a benevolent being in both the games and in the anime... So in other words Pokemon does a much better job representing the Judeo-Christian God than the series that actually uses mythological and religious figures. But I digress, the theme of the Hall of Origin is exceptionally surreal and is honestly MUCH worse than Lavender Town's theme. Though considering you could only reach this place (and by extension Arceus) via an event item or hacking I can understand why not everyone is as familiar with this song.