Seriously. I would post a list of examples of song titles and albums, but that would just make this question way too long and would probably take another year before I can ask it.
Just think about all the songs you know that are about rivers or refer to rivers. Amirite?
On a side note. If someone has a link to every song in existence with the word "river" in the title I would definitely like to see it.
My humble opinion is that a river can be used as a metaphor for a lot of things:
passing of time
forgiveness
life
constant change
cleanliness (of sins, of problems, of worries).
peacefulness
isolation
Most song writers write about life / love struggles and they are closely related well to the stated metaphors.
However keep in mind that the river will be used as a metaphor more in some genres (folk, country, blues, rock) than in others (Rap, urban).
Rivers can be also an scenario and it's very common because people like to go to rivers to swim or simply to just watch the water flow, so it helps to develop the story of the song. The Mississippi river, for example is the scenario of multiple blues songs mainly because the writers of the songs lived near the river.
Some songs with rivers:
My son's name is "River" so I'm very sensitized to the large number of songs about rivers. However, I'm not sure it's just rivers --there's are plenty of iconic natural elements that poets and songwriters refer to often --perhaps because they are part of everyone's life.
Rivers, night, the sky, rain, mountains, winter, spring, summer, fall, storms, stars, the moon. Come to think of it, there's even a song named "Moon River"!
If I had to make a guess why rivers are even more common than most of the others, it's probably because not everyone lives near a mountain or the ocean, but pretty much every major human habitation is near a river.
