|This article is written from the Real Life point of view|
|“||The music played in the background when Samus first receives an order from the Aurora Unit in MP3:Corruption is the music used in 1994's Super Metroid. This music was also born when I stopped my motorcycle on the side of the road on my way home from Nintendo-I recorded the melody by singing. I'm sure people who drove by me were wondering what I was doing. [Laughs]||„|
Theme of Samus Aran, Space Warrior is a music track that appears in Super Smash Bros. Brawl and Super Smash Bros. for Nintendo 3DS and Wii U on the Norfair stage. It is a remix primarily of the credits theme from Super Metroid, but also the intro theme.
Kenji Yamamoto composed the original theme when it suddenly came to him while he was driving home from work. He pulled over his motorcycle and sang the melody into his tape recorder, then played it for Yoshio Sakamoto at work the next day. It then became the theme of Super Metroid. The Super Smash Bros. version was arranged by Masato Kouda/Coda, a composer from Capcom.
The original intro theme from Super Metroid can be heard here, and the credits theme here. Arranged versions of both appear on the Super Metroid: Sound in Action CD, linked here (intro) and here (ending). The soundtrack gives them the names Theme of Super Metroid, Super Metroid Ending and Ending. The introduction and ending themes are also included on Play it Loud! Original Soundtrack Volume 1, a 1996 compilation album from Nintendo Power. 
The remix from Brawl can be heard here: 
Another version of this theme can also be heard in Metroid Prime 2: Echoes, as the theme of the Federation Marines. This version also plays in Metroid Prime 3: Corruption, when Samus meets Aurora Unit 242 in person after obtaining the PED Suit, and again when she speaks to Fleet Admiral Castor Dane on the Pirate Homeworld. This can be heard here. A final remix is included in the ending theme, as Samus's Gunship flies past the G.F.S. Olympus and she transmits a message that her mission is complete. A third remix for Metroid: Other M is present in the trailers (including the one shown at E3 2010), on Metroid.jp and Metroid.com, and in-game in the Story feature.
A brand new remix of the original Super Metroid intro theme is present in Metroid: Samus Returns for the game's introduction, and is featured in the Metroid: Samus Returns Nintendo 3DS Theme and on the Samus Archives Sound Selection CD, titled Theme of Samus. It can be heard here: