One of the things about music is that each individual that listens to a piece of music can interpret it in whatever way they understand the music. The artist has written it to mean what they what it to mean but like other art it is still left up to the interpretation of the listener to take what they can from it.
I think that music, like all art, can reveal aspects of reality that can be seen as both good and not so good elements of being in the world. Much of music can be used to reveal personal pain and trauma. In this way, music can be seen as almost cathartic aspects of personal experience. Music that discusses loss, breakup, separation, or abuse can reveal and serve as testimony to the human spirit. By the same example, some might point to this as so- called "bad" teachings because of the very nature of what is being revealed. For example, if we examine the song, "Numb" by Linkin Park, the so called "good" teachings present is that the song gives voice to the predicament of those who are isolated. Yet, the very same reasoning could be used to examine its bad elements present because it discusses aspects of reality that are not desirable. Along these lines, many can and have argued that gangster rap is an example of music that depicts harsh conditions of life, allowing it to teach "good" and depict aspects of being that could be seen as "bad."
Music can be a good influence on individuals, but it can also be a bad influence. Some music advocate healthy living and are used for education purposes. For example, some songs are used to memorize the alphabet or the process of mitosis. On the controversy, some songs encourages sex and drugs. Some songs with bad intentions can often be about 'getting high' or 'getting wasted'.
Well, music incorporates anything and everything that is going on within this world, to heartbreak, to depression, to love at first sight, to even a song about Friday. It just depends on who can relate with the lyrics and who the song is being directed to. There is this song that caused a lot of controversy within the Korean Pop fandom, where a female artist, wrote a song about unhealthy dieting and being skinny is the way to go. Obviously she is someone who greatly influences young girls and this may lead to them thinking that this is the only way to getting someone to like them.