|This article is written from the Real Life point of view|
Sanctuary Fortress features a lot of electronic instruments that imitate the sound of repetitive beeping at various pitches, giving off a strong "technological" vibe to the song that fits the high-tech aesthetics of the fortress. The bass and percussion rhythms also evoke the traditional desert music style of other Echoes songs such as Luminoth Temple. The melody is performed by a choir or by a high-pitched synth, both of which give this song a much more upbeat and hopeful vibe compared to much of the Echoes soundtrack. The theme uses a Korg Electribe EA-1 synthesizer, preset A06, for the bassline and arp melody.
It is also one of the unlockable songs in the in-game Multiplayer, unlocked when Samus restores the Energy Controller of the Sanctuary Fortress and reports back to U-Mos. In Metroid Prime Trilogy, the song is available in the Soundtrack Gallery, costing one Silver Credit.
The later portions of the Fortress play an alternate version of this theme.
The main theme can be heard here: 
- ^ Soundtrack Gallery
- ^ Metroid Prime 2: Echoes Multiplayer
- ^ SynaMax (synamax). "New #Metroid Prime synth finding! Kenji Yamamoto used a Korg Electribe EA-1 (preset A06) for the arp melody and bassline in "Sanctuary Fortress" from Metroid Prime 2: Echoes!" 6 May 2021 5:03 p.m. Tweet. https://twitter.com/synamax/status/1390411890065543171