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Descending into dungeons is made a moving experience through the accompanying music themes. Throughout the games, this task was managed with different approaches.
Ultima III[]
In Ultima III it is clear that music was still a new feature. The dungeon theme is very short and more of a random selection of noises than music.
Listen to a MIDI version of the theme here: 
Ultima IV[]
The dungeon theme of Ultima IV is much more detailed than in Ultima III. The main characteristics of this theme are the constant and rhythmic bass strokes and its companion, a very high-pitched metal xylophone.
Listen to a MIDI version of the theme here:
Ultima V[]
The main characteristics of this theme, "Halls of Doom," is the high-pitched chorus and its companion, a dark bass instrument. On the Apple II with Mockingboard, this song is played with an organ.
Listen to a MIDI version of the theme here:
Ultima VI[]
This theme has a rhythmic beating of a drum, accompanied by a dark guitar and deep pipe music.
Listen to a MIDI version of the theme here:
This music was revamped for the SNES.
Ultima VII[]
The Ultima VII dungeon theme is not conventional music. It consists of long passages with a continuous bass.
Listen to a MIDI version of the theme here: