There are no formal rules to write a good song. Every songwriter has a different method of writing a song, but there are common trends that separate the good songs from the average songs. This article will explain how to write a song.
John Coltrane said "If I don't live it I can't blow it out of my horn". Sitting in your bedroom hoping something brilliant will strike you is not a reliable method of song-writing. Go out with a pen and paper, or a voice recorder, and make notes for songs in new places. Go for a walk to the graveyard, the beach, the park, the river, the coffee shop, the pub or the forest. By going out, seeing new things and talking to different people, you will have more ideas for songs.
A story is how to make a song engaging. If you start with a simple storyline, then the verses can suddenly be very easy to write, because you will simply be fleshing-out ideas. An example would be: Boy meets girl; he wants to hold her hand; she likes someone else; boy builds a machine to erase the other guy from history; boy and girl hold hands. Each phrase can be expanded into a whole verse, with the rest of the song already in mind. Without storyboarding a song, it can lack focus and the writer can run out of stream half-way through.
When asked about how to write music, Lou Reed said "One chord is fine. Two chords is pushing it. Three chords and you're into jazz." You can write a song with any musical accompaniment, however simplistic or complex. It could be one "G" chord throughout, so long as there is enough interest in the words and the delivery to draw the listener in.
Just sing it
If you have a piece of music that you want to write for, just sing along with it. It does not matter, if you sing any words: just get the melody and the rhythm of the delivery and the words will flow naturally and easily. Paul McCartney wrote "Yesterday" by singing the melody with the words "Egg and chips" (try it); the song evolved from there.
One golden rule
It is something that you will find in all good songwriters and something that defines bad song writers: - Do not tell your audience what to think; instead give them something to think about. Leonard Cohen and Bob Dylan are masters of this art; at their best, they do not preach a perspective or philosophy to their audience, but instead present a story or scene in such a fascinating way that it stays with the listener.