It depends on the beats of the song 😆
Jokes apart, It normally depends on my mood and the mood of the song. When it likes me I'm able to connect someway and feel the author's intention. It also happens the reverse way and suddenly the song fits perfectly with what I'm doing and/or feeling.
If we talk about musical memory It happens to me the same way as with my smell memory .
Sry me but it's a short version of an answer though.
Hope you'll share with us your feeling too XD