Here is a classic: one of the best songs on the Atari 2600, the main theme from Pitfall II: Lost Caverns (1984). This game is pretty amazing coming from a machine that was only designed to play two games: Pong and Combat. The musical score rivals early NES games, and the melody holds well on its own as a nice piece of adventure music. However, what really stood the soundtrack apart was the adaptive audio: upbeat music would play after gold was collected, sad music would play when the player hit an enemy, and if nothing happened for an extended period, background music would play. When the player collects a balloon, the game also plays “Sobre las Olas” (Over the Waves), a famous Mexican song (skip to about 1:35 in this video). The video below contains the three main tunes in the game in a medley. Download link is broken, but here is a different version. It’s entirely in three-channel audio (only three instruments or ‘voices’).
The version I uploaded is an arrange of the main theme and background music. The main theme is very adventurous and immediately hummable. There is even a little of Mickey Mousing here with flutes reflecting Pitfall Harry’s jumping and rope swinging abilities. The second half is a slower version of the theme, and these fifteen seconds get pretty monotonous, so I arranged the track to loop back to the more exciting main theme. The short track lengths are fairly typical in length for vgm of the time, and it’s not like the Atari could store tons of music data in the first place, which makes the theme even more amazing.
Oddly, there have not appear to have been any remixes of this theme. Pitfall II was released for several other systems though, and the version for the arcade by Sega has a remixed soundtrack. Unlike the Atari 2600 version though, it plays the main theme throughout and the background theme in Stage 2. SEGA Arcade 80s Vol. 2 (2003) contains the soundtrack to the arcade version. The game is kind of a mix between the first two games and standard platformer fare.
Though David Crane is a programmer rather than a composer, Pitfall II‘s theme is a notch above most programmer music, which is often either poor in quality or renditions of public domain music (such as Sousa marches, Bach, or Beethoven). Crane’s work includes Little Computer People, A Boy and His Blob, and the infamous Night Trap.