Flagship work · Hirokazu Tanaka · 1986

Metroid

Loneliness Rendered in Three Channels

How one composer turned NES hardware constraints into the sound of alien isolation - and defined the atmospheric dimension of video game music.

Creating Alien Atmosphere

Released on August 6, 1986 for the Famicom Disk System in Japan (and ported to NES cartridge for North America in August 1987), Metroid tasked its composer with something no Nintendo game had attempted before: music that felt truly alien, truly isolated, truly dangerous.

Hirokazu Tanaka’s solution was compositionally radical for its era. Rather than filling the NES’s available channels with melody, as Koji Kondo had done to transcendent effect in Super Mario Bros. (1985), Tanaka left significant sonic space empty - or near-empty. The implied silence was the composition.

The result was something unprecedented: an 8-bit score that felt large - vast cave systems inhabited only by the echo of pulse waves against stone walls, by the slow pulse of a triangle wave bass that felt geological rather than musical.

Metroid’s music is widely regarded as the origin point of the “atmospheric” dimension of video game music - a strand that runs through Castlevania’s gothic chambers, the later Metroid series’s electronic ambience, and survival horror game audio to the present day.

Metroid FDS title screen
Metroid - Famicom Disk System (1986). Sole composer: Hirokazu Tanaka.

The NES 3-Channel Atmosphere Technique

The NES / Famicom’s audio processor (Ricoh RP2A03 in NTSC; RP2A07 in PAL) provides five audio channels:

  1. Pulse 1 - square wave, variable duty cycle
  2. Pulse 2 - square wave, variable duty cycle
  3. Triangle - triangle wave, fixed amplitude, no volume control
  4. Noise - pseudo-random noise (percussion, effects)
  5. DMC - Delta Modulation Channel (1-bit PCM samples)

For the Brinstar theme, Tanaka’s channel assignments (as documented in chiptune community analyses) are approximately:

  • Pulse 1: primary melodic line
  • Pulse 2: supporting harmony or counter-melody
  • Triangle: atmospheric bass pedal tone
  • Noise: minimal - percussion used extremely sparingly
  • DMC: unused or near-silent in most analyses

The absence of full noise percussion - standard in NES game music - and the near-absence of the DMC channel creates the distinctive empty quality that made Metroid’s caves feel genuinely vast. When the noise channel does appear, it functions as a textural accent rather than a rhythmic backbone.

Metroid NES - early game Metroid NES - Brinstar area Metroid NES - mid Brinstar Metroid NES - Kraid area Metroid NES - deeper areas Metroid NES - late game

Brinstar, Kraid, Norfair - Individual Breakdowns

Brinstar

Surface theme - most-heard Metroid track

The iconic entry-point to Zebes. Pulse 1 carries a memorable three-note figure that repeats with harmonic variation; Triangle provides the cave floor. Of all Metroid’s themes, Brinstar is the most melodic - but even here, the melodic content is sparse against a vast implied silence. The theme loops without resolution, reinforcing the absence of a narrative endpoint.

Kraid’s Lair

Boss dungeon - oppressive atmosphere

More minimal than Brinstar. Kraid’s Lair theme abandons the relative melodic accessibility of the surface and descends into heavy, slow-moving texture. The pulse waves move in contrary motion at a reduced tempo; the triangle bass is heavier, more geological. It is a masterclass in building menace through restraint - the theme implies something vast and terrible without stating it directly.

Norfair

Lower depths - heat and disorientation

The deepest and most alien of Metroid’s areas, Norfair’s theme pushes further into abstraction. The melodic content becomes more dissonant, the pulse wave textures more abrasive. If Brinstar is “alone,” and Kraid is “threatened,” Norfair is “lost.” The three themes chart Samus’s psychological descent as much as her physical movement through the planet.

Item Fanfare

Reward cue - brevity as design

Metroid’s item fanfare is among the most minimal in Nintendo history - a short, bright ascending figure that sounds almost intrusive against the surrounding atmospheric silence. Its brevity is deliberate: the game returns to the cave ambience immediately, reinforcing that the world does not stop for Samus. The interruption itself communicates urgency and isolation.

FDS vs NES - What Changed

The Famicom Disk System version of Metroid (1986) uses the FDS’s additional wavetable synthesis channel - a 6th audio channel that can produce arbitrary waveforms by writing 64 4-bit samples. This is conceptually similar to the Game Boy’s wave channel and provides richer, more varied timbres than the NES’s fixed triangle wave.

In the FDS Brinstar theme, the wavetable channel is used to create the distinctive ambient texture that characterises the original version. The NES cartridge port (1987) lacks this channel and must approximate the same passages using only the 5 standard NES channels - the result is perceptibly different, though Tanaka’s core compositional architecture is preserved.

For players who experienced Metroid first on NES cartridge (the majority of Western players), the NES version is the “authentic” Tanaka score they know. The FDS version offers a richer harmonic palette - but the compositional genius is equally present in both.

Samus’s Sonic Identity

Tanaka’s Metroid score did more than accompany a game - it created a character. Before the visual design of Samus was understood by most Western players (the reveal of her gender at game’s end was one of gaming’s first major plot twists), it was the music that defined who she was: alone, capable, moving through a world that did not acknowledge her existence.

The score’s treatment of silence as a compositional element - the implied emptiness of unused channels - perfectly matched the visual emptiness of Zebes’s corridors. Music and environment reinforced each other in a way that few NES games achieved.

Later Metroid titles (the Metroid Prime trilogy, Metroid: Other M, Metroid Dread) have all referenced and developed Tanaka’s original atmospheric approach. Kenji Yamamoto’s Metroid Prime scores are in direct dialogue with the Brinstar and Norfair themes - a lineage that extends across 35 years of the franchise.

“Metroid was trying to create an atmosphere that no Nintendo game had attempted before. The music had to make the player feel genuinely alone in an alien world - not threatened by enemies, but by the silence itself.” - Community retrospective on Tanaka’s compositional approach to Metroid