Thatâ€™s it. Thank you! The exact three chords start at 12 seconds. I have â€˜jazzheimersâ€™ and had remembered the changes in the wrong key in my initial post about this. The key is Ab. The chord in question is a Dmin7b5. Over this chord he plays Fmimaj7, Gmi7b5, Abmaj7#5. The following change is a Db7 over which Bill plays Abmi/maj7, Bbm7, Cbmaj7#5.
The Fmimaj7, Gmi7b5, Abmaj7#5 are really interesting. Nowdays people would automatically plug in the F melodic minor( Ab LA to us) over a Dmin7b5. Why would Evans choose the chords/harmonized scale he did? For one thing there is a momentary â€˜rubâ€™ between the bass playing D natural and the D flat note in the Gmi7b5. Maybe he liked rubs like that. It is possible that these chords were used because with the exception to the E natural note, the chords are more aligned with the overall horizontal scale of the piece, Ab major. So, you could look at it as F harmonic minor or Ab major#5.
Now I have something new to experiment with over mi7b5 passages.
(The changes in the old Real Book donâ€™t match this version but the changes in one of Chuck Sherâ€™s New Real Books nail it)