Past Stages and Melee Stages are special designations given to stages returning from previous installments in the Super Smash Bros. series.
In Melee, three Past Stages were available. They are replicas of their Super Smash Bros. counterparts, complete with music and backgrounds. All of these stages must be unlocked, unlike in the original game. The stages also seem to be slightly larger in size than they were in the original game.
From Super Smash Bros.
In Brawl, "Past Stages" has been renamed Melee Stages. These stages now utilize the functions of My Music, like most stages in Brawl. According to the DOJO!!, the stages are arranged so you get one from each game world.Cite error: Closing </ref> missing for <ref> tag.