Area4 5 Basic

Area 4 & 5 (as named internally) is an ambient theme from Metroid: Samus Returns. It is composed by Daisuke Matsuoka.

Description
Area 4 & 5 is heard in the entrance of Area 2 and the second half of Area 4. It consists largely of an echoing melody played on a glockenspiel or some similar instrument, a harmony performed with bass instruments, and various ambient sounds. It can be heard here:

Area 4 & 5 may be based upon the ambient track originally played in Phase 3 in Metroid II: Return of Samus. This theme, originally composed by Ryoji Yoshitomi, has some similar note patterns to Area 4 & 5; the most obvious similarity is the last four notes, which are identical in both songs. Since Phase 3 corresponds directly to Area 2, this may have been a deliberate reference by Daisuke Matsuoka, although this is not confirmed. This ambient theme can be heard here:

Trivia

 * Despite its internal file name, Area 4 & 5 is not played at all in Area 5.