Definitely a controversial topic in terms of making the simple things quite complicated problems.
So, what is so "evil" about music then?
Music is a patternized sound that can bring about pleasure in hearing it (or from the consequences of hearing it).
Hmm. When you hear something which eventually annoys you, even if it is something as primitive as a continously loud noise, then you want to avoid it. This can be associated to something "evil", though I wouldn't jump to such a scary word such as that.
One music might be liked by person A and might be disliked by person B (and not just because of personal taste - it might be because it reminds them of something personal, like a traumatic incident), so in this way, Person B can attribute the music to be "evil".
So what is the "issue" of music in Islam?
Music is found in virtually every part of the world, and has been since the time that mankind started to develop. I don't know if it's unique to the Qur'an that some people seem to have a problem with it. Possibly connected with the perception of 'invoking evil spirits'. Voodoo, black magic - so-called invocation of emotive feelings and so on.
The real problem for me, is that if the Qur'an said that Muslims should hide their heads in a bucket of sand every week, then this is obviously what they should do.
Does anyone understand this?