From Wikipedia: Tunnels of Doom is a video game programmed by Kevin Kenney in 1982 for the TI-99/4A computer system. Tunnels of Doom is consistently listed by TI-99/4A fans as one of the top games available for the system.
The game is one of the first graphical role-playing video games . Based loosely on the tabletop role-playing game Dungeons & Dragons, it is a standard dungeon crawl adventure in which a player or number of players controls the fates of 1–4 characters as they journey into the depths of the Tunnels of Doom. Despite the lack of a progressive storyline, it possesses many elements duplicated by other, later CRPGs.
The music for Tunnels of Doom was composed by Hank Mishkoff, a TI programmer who also wrote the music for the TI-99/4 Demonstration program and other early TI-99/4 programs. Mishkoff originally created the music for The Attack, an earlier program; however, TI rejected the composition for that game, using it with Tunnels of Doom instead.
Source: Wikipedia, "Tunnels of Doom," available under the CC-BY-SA License.