What should i do about my 2yr olds music taste?

Ask your friends to be respectful enough to not play inappropriate music around him. I have a similar problem. My fiancee's cousins listen to ICP but they know that I don't want my kids to be exposed to that crap, I want them to know what GOOD music is, so they don't play it around them. They did however teach my oldest to say Whoop Whoop, which is fine because they're just words. And while he will hear swears when he gets older you don't want him to think it's okay to swear and be violent, I assume. I'd just ask my friends to please respect my request, if they don't then they don't respect what you want for your son.