Does the background music actually mean anything?

[Famix]

It sounds german in some areas like the amusement park and the village, but I'm not sure

[Nex]

I'm German and I don't think that that's German.... I always hear some fragments like "sky's are green" but I have no clue what they mean... Maybe it's Japanese?

[Nia夕莉]

no they don't

try google up the article about Drakengard/NieR song usually any song sung by Emi Evans and/or composed by keiichi okabe are made-up language by mixing words from 5-6 different language and doesn't have any real meaning behind them.

(another notable composer that does similar to this are yuki kujiura)

[Nope]

Most of the song in this game (and NiEr) use Chaos language - a mix of German, French, English and more

[DeadByLag]

Emi Evans basically formulated the Chaos language - an imagination of what a language far into future might sound like after blending a number of current languages.

https://thekoalition.com/2017/the-music-behind-nier-automata-an-interview-with-emi-evans

[Omoikane]

It may be nonsensical words but the way it's done creates topnotch music and atmosphere.