Surge Concerto Terminal

The Surge Concerto Terminal サージュコンチェルト・ターミナル (saajuconcheruto taaminaru), commonly abbreviated as SCT, is the main control console for the Migratory Ship Soreil, and it is also the mechanism that allows it to harvest energy from the world beyond the Seven Dimensions (our world, Earth). This makes possible for Soreil to continue working potentially forever.

The SCT also houses an incredibly large Song Magic library and it is the main unit that processes the Cielns, so it wouldn't be absurd that it also allows to entirely control to Soreil by merely singing. Likewise, since this system controls all of the mechanisms that allow people to live within the ship, if it gets shut down or destroyed, nothing could live on it anymore.