Ground Theme (地上のテーマ) is heard as you make your way from the Worzen's house to the dungeon. The tune begins with a fade in accompanied by limited percussion and harmony, but grows to become more lively while remaining pleasant. The song is pretty much the same between the NES and MSX versions of the game.
The title is translated from Japanese on the official MSX soundtrack.
Legacy of the Wizard (NES)
Like the other songs in the soundtrack, Ground Theme has a crisper sound on the NES than the MSX. The song is track 13 in the NSF file and plays on the RP2A03.
Dragon Slayer IV: Drasle Family (MSX)
The song for the MSX is a bit more chippy sounding, and the fade in at the beginning of the song isn't as impressive. The song is track 13 in the KSS file and is played on the AY-3-8910 on the MSX and the identical-sounding YM2149 on the MSX2.