When an emotion attaches itself to an incident or experience, it makes for a strong memory. (This is thanks to a close friend who is very biology inclined)
I think therein lies the power of a song. Songs we like (or dislike) typically arouse emotions and these attach themselves to a situation or experience. That is probably why some very depressing songs can arouse laughs and happy memories.. and vice versa. Where you heard the song, who you heard it with etc influences the very idea of the song in our minds after all.
Some songs, however, tend to be universally happy. For example, Summer of 69 is one of them. It is one of those tunes that tends gets everybody happy and singing along..
A thought that crossed my mind today as I was listening to a ‘happy memory‘ song is that we are essentially like songs, every one of us. We all have our own (different) tunes and depending on our mood and general demeanor, we are likely to leave the people we meet with a strong memory..
So, what sort of memory do we want to leave people with? And what sort of memory do we leave people with?