Approaching Sector Zero

"Approaching Sector Zero" is an unnamed theme from Metroid: Other M. It was composed by Kuniaki Haishima and orchestrated by Sachiko Miyano.

Description
This theme is meant to build up to the climax of Other M. It is played as Samus Aran walks through the corridor leading into Sector Zero, while an unseen Baby Metroid watches her. The song stops playing once she notices the Infant Metroid, and is never heard again.

This theme primarily consists of orchestral strings and electronic synthesizers playing repeating harmonic patterns to build up tension and suspense, occasionally punctuated by a heavy and echoing percussion beat or a high-pitched ambient sound. As the song progresses, a female choir is added to the harmony as well, filling out its sound. The melody is a synthesizer set at a high register, performing simple variations of a three note pattern where the second note is the highest, in a manner very strongly evocative of the Title theme.

The theme can be heard here: