[[File:Songs to Test By Collectors Edition Cover.jpg|right|300px]]'''''Songs to Test By''''' is the '''soundtrack''' for '''''[[Portal 2]]'''''. ''Songs to Test By'' was made available free from the [http://www.thinkwithportals.com/music.php ''Portal 2'' official website] in .mp3 format, and a 4-disk Collectors Edition is available to [http://amzn.com/B009DJB8I2?tag=eonstuf-20 purchase from Amazon].
[[File:Songs to Test By Collectors Edition Cover.jpg|right|300px]]'''''Songs to Test By''''' is the '''soundtrack''' for '''''[[Portal 2]]'''''. ''Songs to Test By'' was made available free from the [http://www.thinkwithportals.com/music.php ''Portal 2'' official website] in .mp3 format, and a 4-disk Collectors Edition is available to [http://amzn.com/B009DJB8I2?tag=eonstuf-20 purchase from Amazon].
Shorter versions of particular songs, or sound effects from the game, are available as ringtones from the website above. The soundtrack was released in three volumes: The first, titled Volume 1, was released on May 25, 2011; Volume 2 on July 1, 2011, Volume 3 on Sept. 30, 2011, and as a 4-disk Collectors Edition on October 30, 2012.
The Collectors Edition also includes in-game promotional items for Team Fortress 2, and to & in-game promotional items for Dota 2, and the Turret Lullaby comic.
Vitrification Order by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 2 [6:34] | Download| Play
Music of the Spheres by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 2 [3:38] | Download| Play
You are Not Part Of the Control Group by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 2 [3:24] | Download| Play
Forwarding the Cause of Science by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 2 [3:40] | Download| Play
PotatOS Lament by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 2 [1:59] | Download| Play
The Reunion by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 2 [3:45] | Download| Play
Music of the Spheres 2 (Incendiary Lemons) by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 2 [2:43] | Download| Play
Portal 2: Songs to Test By - Volume 3 (Collectors Edition Disk #3)
Album: Portal 2: Songs to Test By - Volume 3 by Aperture Science Psychoacoustics Laboratory
Reconstructing More Science by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [2:36] | Download| Play
Wheatley Science by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [2:29] | Download| Play
Franken Turrets by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [4:08] | Download| Play
Machiavellian Bach by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [4:01] | Download| Play
Excursion Funnel by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [4:32] | Download| Play
TEST by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [6:14] | Download| Play
The Part Where He Kills You by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [3:23] | Download| Play
Omg, What has He Done? by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [2:24] | Download| Play
Bombs for Throwing at You by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [5:48] | Download| Play
Your Precious Moon by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [1:55] | Download| Play
Caroline Deleted by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [1:50] | Download| Play
Cara Mia Addio! by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [2:33] | Download| Play
Want You Gone by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [2:21] | Download| Play
Spaaaaace by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [0:45] | Download| Play
Space Phase by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [1:32] | Download| Play
Some Assembly Required by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [1:50] | Download| Play
Robot Waiting Room #1 by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [2:14] | Download| Play
Robot Waiting Room #2 by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [2:14] | Download| Play
Robot Waiting Room #3 by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [2:14] | Download| Play
Robot Waiting Room #4 by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [2:14] | Download| Play
Robot Waiting Room #5 by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [2:14] | Download| Play
Robot Waiting Room #6 by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [2:06] | Download| Play
You Saved Science by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [0:47] | Download| Play
Robots FTW by Aperture Science Psychoacoustics Laboratory on Portal 2: Songs to Test By - Volume 3 [3:38] | Download| Play
Collectors Edition Disk #4
There are no downloads because it's a copyrighted disk.
Album: Portal 2: Songs to Test By by Aperture Science Psychoacoustics Laboratories
Subject Name Here by Valve Studio Orchestra on The Orange Box Original Soundtrack [1:44] | Download| Play
Taste Of Blood by Valve Studio Orchestra on The Orange Box Original Soundtrack [3:06] | Download| Play
Android Hell by Valve Studio Orchestra on The Orange Box Original Soundtrack [3:45] | Download| Play
Self Esteem Fund by Valve Studio Orchestra on The Orange Box Original Soundtrack [3:30] | Download| Play
Procedural Jiggle Bone by Valve Studio Orchestra on The Orange Box Original Soundtrack [4:34] | Download| Play
No Cake For You by Valve Studio Orchestra on The Orange Box Original Soundtrack [4:05] | Download| Play
4000 Degrees Kelvin by Valve Studio Orchestra on The Orange Box Original Soundtrack [1:01] | Download| Play
Stop What You Are Doing by Valve Studio Orchestra on The Orange Box Original Soundtrack [4:00] | Download| Play
Party Escort by Valve Studio Orchestra on The Orange Box Original Soundtrack [4:21] | Download| Play
You're Not A Good Person by Valve Studio Orchestra on The Orange Box Original Soundtrack [1:24] | Download| Play
You Can't Escape, You Know by Valve Studio Orchestra on The Orange Box Original Soundtrack [6:24] | Download| Play
Still Alive by Jonathon Coulton on The Orange Box Original Soundtrack [2:56] | Download| Play
Still Alive (J.C. Mix) by Aperture Science Psychoacoustics Laboratories on Portal 2: Songs to Test By - Volume 4 [2:57] | Download| Play
Please note that the Trivia section consists purely or mainly of recurring melodies.
This section also may be considered as a spoiler for people who would like to listen to the OST themselves.
The second part of 9999999 is actually a remix of Music of the Spheres I.
The track The Courtesy Call has its first part unique to itself, the second part is a sped-up version of Music of the Spheres I and the last part is a slowed-down version of Reconstructing More Science
Likely made to reflect on the entire game before, Caroline Deleted contains a snippet from The Courtesy Call at the very beginning, a few lines from Cara Mia Addio! right after that as well as a few looping notes from Music of the Spheres I both as deep and slow and as high-pitched and fast. The song then changes to a remix of Reconstructing More Science, ending on the buzzing noises from Don't Do It.
Similarly, I'm Different contains a few tones from Bombs For Throwing at You. They are however hard to recognize, as an extra tone with a different frequency is added right after an original one - only the quiet melody connects it with the other track.
[[Media:Template:Dictionary/audio/i am not a moron|Download]] | 
[[Media:Template:Dictionary/audio/i am not a moron|Play]]