Nanana

I think this song is about a (young) man falling in love with a (beautiful) girl; however, the odds are not in their favour ("grey grey world where nobody sings"; "in a place where hell is around the corner"; "if you wanna live you better not touch"): this could hint at a situation close to a civil war - either "small", like Catholics and Protestants in Belfast, or "big" like during the American Civil War, where you could get killed by your own people when they saw you with "the enemy".

Instead to fight for his relationship with the "human doll" he leaves the country ("I left the one that I loved behind"). He returns after some time, only to find out that he cannot get back to the girl. The "Black Swan" could either refer to another man, or - what I think is more likely - it's a symbol for death, meaning the "human doll" has died meanwhile.

The song she sang to him is played in the radio (probably because he turned it into a "suitable" song), and since many people listen to it, she won't be forgotten.

In my opinion, the whole song refers to the creative process, the life and sacrifices an artist has to make, in an less literal way. The human doll refers to a muse, may it be a flesh and bone one, a girlfriend, or a metaphoric one. The artist is "kissed by the muse" and receives the gift of singing ("I could feel the song going down my throat"). This makes the young artist want to travel around the world in search of fame, but this has consequences concerning his friends and family. His father (who let's remember, founded the band), is well aware of the "touch of the muse" and the sacrifices one has to make in order to become an artist. The now famous artist returns to his origins, and realises how much he has lost. But still he left the world his legacy ("my generation sings with the radio on..."), the song inspired (why not) by the beautiful girl he loved as a young man.