There's an old song by Henry Clay Work called "Come Home, Father" in which a child begs his father to come home from the bar because his little brother Benny is very sick. Hours pass, the father is still at the bar, and little Benny dies. (It was one of my father's favorite songs as a kid!)

Nicolette Larsen sang a beautiful song called "The Angels Rejoiced" about a father who finds religion after his wife dies.

And there's a wonderful song about stepfathers--I'm not sure who wrote it or sings it, but it has the line "I hope I'm at least half the dad, that he didn't have to be." [He Didn't Have to Be, by Brad Paisley]