Treasure Chest (宝箱) is the jingle that plays when you unlock a treasure chest in the dungeon. The jingle is pretty much the same between the NES and MSX versions.
The title is translated from Japanese on the official MSX soundtrack.
Legacy of the Wizard (NES)
The jingle for NES has a slightly richer sound then the MSX version. The song is track 15 in the NSF file and plays on the RP2A03.