Kudos ~ you've tempted me to a bit of prosody . . .
If each of these lines were graphed in terms of accent per syllable
I think it would in part illuminate how and why these lines are effective
On The Panting Mare
I like that. The image of nightmare as runaway horse . . .
Alone Through A Darkened Night DUM DUM dada DUM da DUM
Can you hear the trepidation in the beat of this line?
Someone Wake Me Up DUM da DUM da DUM
It's the same underlying beat as the first line, and we are running, aren't we . . .