You can tweak forever if you want to. You have to be able to set time limits and accept it for what it is at this point in time or you will never finish anything. So to me, it's finished when all the components I want to add to a track are in place and have been mixed, then it's time to move on.
Eek! If it were up to me, I would change a song every single time I play it.
No, I do not know when a song is finished, usually. I do need someone to say "stop" and help me allow something to be what it is. I don't worry too much about this, though, because I think I have the right, as a creator, to play a song differently every time, if I want.
I will say that there are some pieces, especially electronic music compositions, that I can leave be- just because I don't usually play them live.
you feel it
I feel it. Sometimes I cry. I explote in emotion.
when I hear it and it pleases me completely, when I realize that there is no more an idea or within it.
As soon as I'm 100% happy with it. When I'm listening back and can hear all the ideas and thoughts have materialised. I've been known to bang out a song within 60 minutes and be happy with it, but on the flip side I've taken a whole month to finish a song. It really depends on what I can see for the track and what I want out of it. I'm always writing ideas down, writing hooks, punchlines etc. So when I've got all the subjects covered, I'll wrap it up (literally).
Someone who you trust, it could be a parent, cousin, friend or lover, maybe even your brother, says "that's a good song". It is all in other peoples' eyes (ears).
I usually have a song finished in pre production before I take it to the studio to actually record the final version. On occasion I will listen to a record after it's recorded and make some necessary changes post production.
I always find new ways to make a particular song I made better, and that drives me insane. I usually know when a song is finished when I have become absolutely maddened by the thought of hearing the same beat numerous times.
when I can hear it in my head without the finished version recorded.
It just feels right when you recite it to yourself 4 times
I just know. That's why your interviewing me, correct?
I don't think a song is really ever completely finished. There's always something that can be added to make a song more full.
Song structure should be simple. Anything over 4 minutes is probably too long.
I wrote the lyrics, and compose the guitar sections. Then I show my bandmates, and they suggest something if any, or if they like, we start to rehearse the song.