This is very often called musique concrète, or avant-garde as a broader term.
The technique you are mentioning is also referred to as ready-made or found object (objet trouvé in French).
A ready-made is an object/sound/whatever that already existed without any artistic context, which is then turned into art by giving it that artistic concept.
Two
relatively well-known examples are Revolution 9 by the Beatles, and Several Species of Small Furry Animals Gathered Together in a Cave and Grooving with a Pict by Pink Floyd
(yes, that is the title of a song).
In Revolution 9 , you'll notice that the sounds aren't actually aligned to a musical rhythm per se.
This is usually the case with musique concrète:
you throw all rules about music overboard, and create what you think sounds good.
In Several Species (...) , the sounds are not actually natural; they're all created by Roger Waters tapping/slapping his own body in various places, making weird sounds with his voice, and speeding all of this up quite drastically.
In this song, everything is aligned rhythmically, so it's a good example of how far you can go with this kind of sound
: you could even adapt the pitch of each sound to create whatever melody you like.
Anything is possible with this kind of stuff, as long as you're imaginative and creative enough.
:)
Links : Revolution 9 Several Species Wikipedia page for Found Object
music.stackexchange.com/users/6524/Lee White
You can call it in various ways, depending on the style of production / performance.
It can be called Found Object if you are using sounds like you mentioned without performing it.
It can be called Experimental, if you are improvising it - sampling it live.
You can call it Experimental Electronic if you are using your computer / digital sampler.
You can call it ambient, References: http://en.wikipedia.org/wiki/Found_object_(music) http://en.wikipedia.org/wiki/Experimental_music
music.stackexchange.com/users/13642/visualex
You could call it "Industrial Music".
John Cage, Phillip Glass and even Rassahn Roland Kirk (beating on metal chairs to accentuate his enthusiasm...") used this concept quite a bit.
music.stackexchange.com/users/22923/Arkley
In the RPM community we refer to this as Spoon Dropping.
music.stackexchange.com/users/70175/user70175
While not a term for this genre as a whole, this thread would be incomplete unless someone mentioned the practice of sampling .
Hip-hop and electronic musicians (as well as those in other genres) often sample sounds from other music, lines from TV shows and viral videos, and environmental sounds like rain and car horns.
Sometimes the sounds are autotuned and/or edited to have a certain melody, and other times they are left as-is and the interest comes from how the new song recontextualizes the sampled content.
Wikipedia has a good article.
Sampling has spawned many debates about authorship and originality, and the way that hip-hop artists borrow samples from each other (often without giving explicit credit) has been used as a metaphor for the internet and open-source practices as a whole.
See remix culture and Cory Doctorow, Information Doesn't Want to Be Free .
music.stackexchange.com/users/59213/Max
Is there a term for music composed of everyday sounds (animal calls, cars honking, etc.) that are timed just right to sound like music together? (I hope this isn't off-topic here)
Is there a term for music composed of everyday sounds?
music.stackexchange.com
<terminology>
music.stackexchange.com/questions/24201
music.stackexchange.com/users/13789/MaxB
Music composed from everyday sounds is very often called musique concrète, or avant-garde as a broader term. The technique is also referred to as  ready-made  or  found object  (objet trouvé in French). It can be called Experimental, if you are improvising it - sampling it live.  You could call it "Industrial Music". In the RPM community it is referred to as Spoon Dropping.   There are numerous terms that can be used to describe this concept, including "musique concrète", "found object", "experimental" or "industrial music".
There are numerous terms that can be used to describe this concept, including "musique concrète", "found object", "experimental" or "industrial music".