Past and Melee Stages
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 Super Smash Bros.. 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" are named as 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 the player can get one from each game world. Only universes with more than one stage in Melee were selected, however. Unlike the Past Stages of Melee, some Melee Stages have had minor edits (which are listed below). Also, every universe represented in the original Super Smash Bros. has a past stage.
 Changes in Super Smash Bros. Melee stages
It should also be noted that most (if not all) of these stages are smaller compared to the characters than they were in Melee, possibly due to the character models being larger in order to provide more detail. Also, some of the music sounds slightly different than it did in Melee. Furthermore, the Pokémon Trainer gains platforms in the background.