I could at least give you a little more insight from English-speaking bands.
As someone here already rightly wrote, “indie” actually just means that it can’t be clearly assigned to a certain style. So unusual in style, perhaps a little more complicated. But often similar to pop or rock, because bands are often referred to as indie pop or indie rock. But I think that almost all bands want to use this name for themselves because it sounds more interesting. There are also many old bands that used to be called rock or pop bands and are now considered indie. e.g. “The Smiths” Which band would like to be called a pure pop or rock band and not an indie or partly that?
I would now like to list bands that I have googled as “indie”.
The first band that was recommended to me and was described as indie was Animal Collective. I particularly like her albums “Merriwater Post Pavillon” and “Centipede HZ”. It’s a matter of taste, of course, but I’ve enjoyed listening to the first album all the way through many times. Her singing and style sound like pop on the one hand, but also somehow “extraterrestrial”. “. Detail on the side: The picture alone fascinates me. Because nothing moves, but as an optical illusion it looks like this:
https://www.youtube.com/watch?v=Ebmp2YMIr9s&list=PLNPGM2D7aODddI-R2IfE7qMdeKfyO4jUh
Just this year I discovered what is also known as an indie band “Highasakite“. Her album “Mother”:
https://www.youtube.com/watch?v=sLMIC5QcIE8&list=PLGY7CF1o5PA1LoGW3mlYIIqL516MMuu91
“The Notwist” are only known to me by name, but they are also indie, and here are examples:
https://www.youtube.com/watch?v=Uhgxr47tAMs
Here is an album of theirs called “Shrink”:
https://www.youtube.com/watch?v=r01sfsVKQLM&list=OLAK5uy_mjRIQ5fOUg_M10ODsBNUInFsIAy660iiM&index=1
They are a pretty well-known band Imagine Dragons:
Here is the album “On Top Of The World”, also with the well-known hit “Radioactive”. But a lot is known about them, even the first number alone:
https://www.youtube.com/watch?v=p8TfilfFrvg&list=PL0QyBDMHGCNm0lImEPVTTgwlmbmdszlkw
Also “Florence & The Machine” are considered a well-known indie band. Here is their album “Ceremonials”:
https://www.youtube.com/watch?v=S4D_ZSNza9o&list=PLH9WbNQwh6jetSqiH6B-T8Uitok9FkBaD
Von “Vampire Weekend“I particularly like this album:
https://www.youtube.com/watch?v=MrVkKAylpF8&list=PLpSMVsIRq-N9T7IXvGJYZc93CUYE31VtQ
Marina (formerly “Marina & The Diamonds” is also considered an indie singer. Here is her album “Love & Fear”, and like the other artists she of course has several albums. I particularly like the song “To Be Human” from here.
https://www.youtube.com/watch?v=zat62D2QzVM&list=PLlq7Qg7QtlOF9A4kATRSa54aSvIOqJnum
And you can see that there is a lot. More and more similar things are appearing on YouTube and of course you can always google them.
