Some people claim that listening to certain music causes at least some people to act in ways they would never have before. Examples could be that heavy metal might make people angry and/or violent. Another might make people use drugs because it promotes the use of the drugs or do other illegal activities that are promoted. There are cases were people have referenced or testified that some music made them do whatever it was that they were on trial for. I believe that is just pure advice from their Defense attorney. You can use energetic music to motivate or pump up a team before a sports game, or an army going to war, but they must want to be pumped up. The same applies to someone who kills someone else or themselves, they already had an inclination towards such behavior. Music cannot make us do what we have not already chosen to do.
Well, it can have different rhythms that make people sad. For example the blues. It can have lyrics that talk about depression or anything. Every piece of music has a different tone to every person. I don't know that it is negative all the time though. Music can always lighten your mood! It just depends what type!