Can't Get the Song down

I am hooked on a song and am trying to learn the words of it — I only know some of the words. So, I reviewed the lyrics along with the song a dozen times.
On my way to the chiropractor yesterday, I listened to the song in the car and couldn’t get more than four lines figured out. Frustrating. Why couldn’t I figure out some of the words without the script?
What song? No way. I’m too embarrassed to share. One hint — it’s from a musical.