That depends on a lot of things;

1. If it's interesting enough to keep checking out, half a minute up to a minute

2. If I can stomach the vocals, mere seconds - if not it's out the door at once. Much the same with instruments and instrumentation too, but the vocals are in my mind even more essential

3. Is there a potencial there, could the songs grow on you - can't really give a timeline for that

4. Do the song in question just happen to be so catchy that you might grow tired of the whole thing after spinning it a few times... Must have had the chance to hear it a couple or 3 times

5. Am I in the right mood for this kind of music right now or am I in the mood for something else.....??? The same answer as in my 3'rd point

6. Obvious passages, you know when you "can hear the next note or passage" before you've actually have heard it .... nothing that grips or challenge you as a listener..... a minute or so....

7. Chorus, more important in some generes than others - in AOR or Melodic Rock very important. In 70's Prog not that important at all

8. Production, in mere seconds here too

9. Hard and Heavy just for the sake of being Hard and Heavy -
with no understandable substance apart from noise or - mere seconds

10. Too much repeated passages and riffs, going nowhere - one spin through the song

11. Who is involved, I tend to give artists and bands that I already like/appreciate more chances than I would do to new blood.... therefore no particular timeline here either

12. Generes, some things I just can't stand.... seconds again

13. Gritty, brash, all attitude - not much else that grips me ... seconds

There would exceptions to these guidelines too, and music to me is all about how it makes me feel - but I think that if many or most of them ticked the boxes (or even a few if they were "wrong" enough) I would have a hard time letting it into my collection