English rules of grammar are frequently broken even in everyday speech, but there are only rare instances where this is a good idea. Being able to break grammar rules is tied up in culture. For instance, in the southern US, native people often have a different way of expressing verb tenses. The problem is, if someone who is learning English tries to speak like an American Southerner, it is culturally inappropriate. It is even culturally inappropriate for an American who is not an American Southerner to use this form verb tense. Thus, anytime you find an English sentence with poor grammar, do not emulate it. Just realize that English speakers are a diverse group, but there is a standard that we must uphold for 10-20 years before we understand where alternate grammars are appropriate.

In popular music the lyrics are often not grammatically correct. It gives songs a more "common" appeal by using the same grammar as many uneducated native speakers.

Yes, In songs, poetry and even literature grammar rules are often ignored to make the lyric or stanza scan better. It is often referred to as "poetic license".

you are exactly right. But that happens a lot in english music. Rules are being ignored to make something sound better. For the most part it still gets its message across. Also if you listen to like rap music or pop music you will hear alot of this stuff. Also alot of slang terms that are hard for english speaking people to get haha. So all we can do is just go with it haha. I guess the main point is, don't try to learn english from songs if you want to speak english correctly. But it is also good to listen to this stuff to get a look at the culture or to learn some slang.

You are right but singers and writers often ignore correct grammar.