Hello Hendrik,

Hendrik Boom - 22.12.18, 04:23:
> ls -l lists them like this:
>

> -rw-r--r-- 1 hendrik hendrik       0 Sep  1  2007 06 - Track 6.mq3
> -????????? ? ?       ?             ?            ? 07/TRA~1.MP3

???? instead of useful metadata can be a sign of filesystem corruption.
There might be something in kernel log about that.

I'd try fsck.vfat and if that does not work use photorec from the
testdisk package to recover the image.

Best of success,
--
Martin