In the Philippine sub-culture, (I don’t know if it’s an official thing or anything, but hey, it counts if a majority follows it right?) we have the term LSS, meaning Last Song Syndrome. I think I read somewhere that it’s synonymous to the “ear worm” or something.
However, the LSS factor means that it’s the song stuck in your head because you heard it somewhere, but there really is not much significance or point of the song, just the fact that it was the most recent thing that you heard. Sentimental songs (how I like to call them) are long-lasting, memory-invoking pieces that make you remember a distant past, to the point that you almost forgot it until BAM!, this song comes on TV or anywhere else.