Browsing through the music subreddit, I came across this post. An ambient musician by the name of Scott Byrnes has just released a new album titled Aegri Somnia. The full album is available on his page http://scott-byrnes.com/ for free. It's published under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License. What this means is you can download it, and remix it freely, as long as you allow others to do the same.
The album itself consists of four tracks, divided into Night and Day. In Night we have Tenebris (15:50) and Metus (13:02). In Day, there's Diliculo (14:16) and Laetans (17:27). Though he describes it as ambient, it's perhaps more specific to describe it as drone music. The only instrument used is guitar, and it serves to paint the musical spectrum a certain shade, but it doesn't go to any unconventional or plain weird areas. The long track length might not suit people with a very short attention span, but is the perfect companion for long trips such as airplane rides when you just want to doze off with calming sounds.
The album is only available as a zip download, so if you want a preview before downloading you can listen to it free on last.fm, and also download the tracks from there as well.
Edit: As pointed out below, it's now streamable on Scott Byrnes' website.
The album is now fully streamable at http://scott-byrnes.com/