From the Original Broadway Cast recording
Maybe not the best song in the show, but probably the most widely known; I love this song for it's anthem-like quality. Dr. Jekyll sings this before he tests his breakthrough formula, he's convinced that all of his work has lead to this moment. Just like "Music of the Night" it starts without introduction, a whisper of song, growing in strength and intensity as the song progresses. Low drum beats and a bassline-fueled melody add this overall grand nature of the piece. The piano accompanimet is very chordal, letting the solo voice to carry the momentum forward. Tremolos in the strings add a sense of urgency. Building throughout the first and second verse, a cascading drumbeat and the entrance of horns bring us to the third verse, where the song takes off. The bass line continues with a number of leading-tone chords up and down, really pulling the listener along. Before the final verse we change keys from E major to F major, cranking up the intensity as the singer hits strident high G's to punctuate the joy of a lifetime of work paying off.
The basic harmonic structure of this piece is I7-ii7-I7-vi-iii7-ii7-V-ii7-V repeating over and over. Notice the circle of fifths progression which helps drive the song along. With inversions the bass often moves stepwise between those chords, lending even more to the anticipation of the piece. The orchestra arrangement is very full because of the use of many 7th chords, which also create interesting dissonances, perhaps foreshadowing that this "moment" might not be as perfect as Jekyll thinks it is.
Emotionally this piece is one of those that I put on when I'm in (or want to be in) a great mood. This song is an "everything is right with my world" anthem. I may have had a hard day, or something is trying my patience, but after I pull through my moment will come.