[Lunatique]

Whenever I need to focus on mental-intensive work but still need to have some background music to help enhance my concentration (as opposed to distracting me with distinct melodies, rhythms, and lyrics), I will put on my ambient/soundscape playlist. I thought I'd share some of what I listen to, so those who have similar needs could try these, and others could add to this thread with more suggestions.
 
The most important criteria for this type of music/soundscape are:
 
-No prominent sense of rhythm or overtly strong drum/percussion
-No overtly distinct melodies
-No distinct lyrics or vocals (unless used like a synth pad or soft choral wash of sound)
-No harsh and jarring sounds or random distinct noises to jolt you out of the "trance"
 
Here are some examples of what I currently have on my "Writing Soundtrack" playlist, which is what I listen to when I'm writing my novels:
 

 

 

 

 

 

 

 
And since I only listen to this type of music/soundscape when writing, I also categorize them into "Dark and moody," "Light and soothing," and "Scary and disturbing," so I can match the mood to the scene I'm writing.

 

[mjolnir1989]

Personally, I find music by artists like Christian Fennesz and Tim Hecker helpful. If that music sounds too glitchy/abrasive, you can't go wrong with Brian Eno!

 

[muziq]

http://www.discogs.com/Gas-Nah-Und-Fern/release/1363736
 
Gas' Nah Und Fern box, originally four different records released by Mike Ink under his Gas moniker, are my go-to concentration tracks.  Certain CDs will have some rhythms, but it's usually very subtle and compromised by the deep and wide synthscapes.  
 
I've also been gravitating towards James Leyland Kirby's more recent releases under Leyland Kirby, The Stranger, and his last couple of Caretaker releases.  More orchestral and sampled, but very dense and dream-like.  
 
 http://www.discogs.com/artist/1550794-Leyland-Kirby
 
Robert Henke's Layering Buddha is another personal favorite.  He takes the sound samples from the Buddha Machine sound boxes and constructs new ambient and drone tracks that are way beyond the original lo-fi samples.
 
http://www.discogs.com/Robert-Henke-Layering-Buddha/master/84722

 

[moriez]

Lunatique, good track that Warm Pills. Here's a few that I think might end up in your playlist:
 
billow observatory - billow observatory
easychord - not in my family tree
field rotation - fatalist: the repetition of history
gastón arévalo - rollin ballads
relmic statute - untitled
sonmi451 (multiple releases)
william basinski - a red score in tile

 

[inertianinja]

you hinted at it - check out video game soundtracks. there was a post on reddit about this - it's designed to keep you engaged without distracting you.
 
Check out these soundtracks:
Sword & Sworcery
Mass Effect (1/2/3)
Hotline Miami
Bastion
Braid
Broken Age
Journey
Pixeljunk Eden
Skyrim

 

[Lenni]

 though is not ambient's, this works for me playing at low volume in the background. I find vocals in general most distracting when have to focus on something.
 
 

 

[ag8908]

Doesn't exist. Your concentration is best in dead silence.
 
Edit: I'm not an expert, but I recall studies showing that if you are performing a new task, the kind that requires the most concentration, you will perform it best in silence. If you are doing repetitive tasks that could become boring, then music can help because it will act like coffee and elevate your mood and attention. But in that case I recall reading that up tempo music might be best. That mellow stuff you linked isn't useful for anything but causing you to get sleepy, I think.

 

[Happy Camper]

White noise?

 

[2jono]

The Necks .. Aether
 
http://www.discogs.com/Necks-Aether/master/65191

 

[Lunatique]

  Doesn't exist. Your concentration is best in dead silence.
 
Edit: I'm not an expert, but I recall studies showing that if you are performing a new task, the kind that requires the most concentration, you will perform it best in silence. If you are doing repetitive tasks that could become boring, then music can help because it will act like coffee and elevate your mood and attention. But in that case I recall reading that up tempo music might be best. That mellow stuff you linked isn't useful for anything but causing you to get sleepy, I think.

Nope, doesn't make me sleepy at all. It enhances the mood I want to write in and does not interfere with my thoughts. I have separate ambient playlists for light mood, neutral mood, emotional mood, tense mood, dark mood, and horror mood. I match the mood to the scene I'm writing, and it works very well. The lack of distinct melodies and rhythmic elements makes it nearly impossible to distract you, but really helps build the right mood. 

 

[StratocasterMan]

Have you ever listened to any Stars Of The Lid? It may meet your requirements. Give it a try and let me know what you think. Here's their album called "And Their Refinement Of The Decline." It's two hours long.
 
 

 

[WraithApe]

A few suggestions on the darker end of the ambient spectrum:
 
Anduin - Abandoned In Sleep
David Sylvian & Holgar Czukay - Plight & Premonition
Iszoloscope - Les Gorges Des Limbes
Raison d'être - The Stains of Embodied Sacrifice
Robert Rich & B. Lustmord - Stalker
The Haxan Cloak - Excavation
Tim Hecker - Ravedeath, 1972
Xela - The Dead Sea