Is "We are listening together to music" wrong? English is not my mainlanguage, I'm German
There's no "de" in the Dutch sentence so there's no "the" in the English one. Here you are talking about music indefinitely (i.e. any music, or music in general), not specific music (you would use de/The for this)
Not so obvious. I've never heard or seen "I listen to music" in English. It has been always "I listen to THE music". The same as with kitchen - "I cook in THE kitchen, not "I cook in kitchen". It doesn't matter, how it is in Dutch - as far as I know, there should always be "THE" before music in English.
When you say "the music" you are specifying the music that is playing (Ex: you are in a bar and say "I am going to go listen to the music that the band is playing"). Without "the", you can be listening to any music that is playing.
If you want to zone out and put in some headphones, you can say "I'm going to listen to music now."
Other examples, without "the": Mother: Amanda and Sara, what are you doing? Amanda: We are listening to music ! Mother: The both of you? Amanda: Yes, we are listening to music together. Mother: What kind of music? Amanda: Whatever is playing.
Father: Do you want to join in a game of Monopoly? Son: Can't, I'm busy listening to music.
Friend 1: Do you ever listen to music? Friend 2: Yes, I listen to music !
I listen to music all the time.
Examples of specifying, with "the": We should listen to the music that's playing on the radio
The music coming from across the water is wonderful.
The music on the radio is really good.
I agree with that, but why can't it be "We listen to music together"?