This Bill Evans song follows the tradition of other waltzes like My favorite Things and Bluesette by using an extended song form. That is the biggest challenge with this song. I would call it AABAC, with each of those sections being 16 bars.
In the A sections, the chords are inverted more often than not, with the bass playing the 3rd, 5th, or 7th instead of the root. This inversionthe song more of a "Broadway musical" sound than cool jazz. Of course when Bill Evans played it, there was never any question a jazz master was at the keyboard.
The bass line in the A section is real genius as it moves downward chromatically in a truly elegant way. Musicologists refer to this as "suspended tonality." But the soloist must not be distracted by that. You won't find the tonality in the bass during these passages and you might not hear the roots clearly in the other instruments. The chords themselves are not terribly exotic. You just have to learn the chords and appreciate that the bass is adding a completely different quality at those moments.
In the bridge, the bass is on the roots throughout and in the final 16, the bass has a few measures lingering on a pedal C, giving it a more conventional jazz sound.
Evans often played this song as a rubato waltz for one chorus, then went into a swinging 4. For this practice track, we stay in jazz waltz throughout. The last time, the final phrase is tagged twice.