I had an Iron Maiden brainwave the other day!

 So as I was listening to the Iron Maiden songs on my iPhone the other day I came to the conclusion that if I didn't want to listen to ALL my Iron Maiden songs at a time (I've got 11 on my iPhone and they get looooooong), I could split them up depending on the time of day, because some sound better in the daylight and others sound better at night.

Daytime songs:
"Wrathchild"
"Run to the Hills"
"The Trooper"
"Aces High"
"Different World"
"Isle of Avalon"

Nighttime songs:
"The Number of the Beast"
"Fear of the Dark"
"El Dorado"

Any-old-time songs:
"Hallowed Be Thy Name"
"2 Minutes to Midnight"
(aka: my personal favorites)
 

...As I think of it I could probably do the same for my Judas Priest songs (though I only have six of those and there's a bit more overlap)

Daytime songs:
"Breaking the Law"
You Got Another Thing Comin'"

Nighttime songs:
"Living After Midnight"
"A Touch of Evil"

Any-old-time songs:
"Electric Eye"
"Painkiller"