Even just the fact that the artist gets to specify the play order. Today it's rare that a playlist will even have two songs from the same artist in sequence, but in olden days you could have a sequence that was greater than the sum of the parts. My favorite example is the last 3 songs on side A of The Cars Candy-O - Double Life is kind of relaxing, Shoo Be Doo cranks up the tension, and Candy-O starts with a crescendo that releases the tension. I don't actually know if that was intentional, but it feels like it was.
