What do you mean by melodious songs?

It means it sounds good. Easy on the ears. For a full definition see www.answers.com/topic/melodious

If you are referring to the song by A Day to Remember: This song is about a guy who is in love with a girl. He has to leave (for the writer, this probably meant tour) for college, financial reasons,...

it eans that its something wrong with your mind and you can most of the time act really wired and sometimes be clased as a psyco and to shut it short it means a disuse of the mind

It means you like a song the most