Amelia's great, but to me Joni's ultimate travel song will always be Don Juan's Reckless Daughter with its beautiful imagery of snakes and eagles and that white-hot moment when the shadow of the airplane she flies away in crosses the shadow of the train bearing her lover away and her awareness of him is immediate and visceral: "to me it was skin to skin!" She writes like a painter. The music here isn't as complex as the music in Amelia, but the imagery is surreal. Below are my favorite excerpts from the lyrics:

snakes along the railroad tracks / eagles in jet trails
coils around feathers and talons on scales
gravel under the belly plates / wind in the wings
big bird dragging its tail in the dust / snake kite flying on a string.

there are rivets up here in this eagle—there are box cars down there on your snake
and we are twins of spirit—no matter which route home we take or what we forsake

I touched you on the central plains-it was plane to train, my twin
it was just plane shadow to train shadow, but to me it was skin to skin