Walrus

Hey do any of you musicians or music fans know how a band or performer gets their song submitted to be featured on a tv show or movie? How does that work? Which websites could you submit to that you may know of? Or is it all based on luck and who you know? I've got a friend and I think he has some really good songs and I'd like to help him. Or any tips on helping get a song heard. I know I get these invites on YouTube all the time by musicians trying to get their video liked. I don't think my friend would like that kind of promotion. Any tips would be appreciated.