I really dont think this question can be fully answered. There are so many different kinds of people, cultures, in this world that influence the music we hear. To make a statement of what is a good tune is very very difficult because everyone likes something different then the next person especially in Music. Sometimes even songs that don't sound good to "YOUR" ears will be the greatest song to another person.We all percieve a tune in a way that is personal to us as individuals. Music comes from within and thats where the hard part in answering this question lies. It's the same with all the arts, music, painting, acting, etc etc. When you can just see thru the artform and understand what the artist is saying this is the start of the process. Remember whats "GOOD" to you may not be "GOOD" to the next guy.