Sure thing @richard18 - I will pass this onto Jovino.
In the interim, here is some information that you should find helpful to analyse the triad options.
Looking at the first 3 bars of “Alone Together” let’s examine where these triads come from:
For the D-7, the triads are coming from the 7th chord and extended chord tones:
D-7 = D-F-A-C (notice the F triad is 3-5-7 of D-7)
D-9 = D-F-A-C-E (notice the A- triad is 5-7-9 of D-9)
D-11 = D-F-A-C-E-G (notice the C triad is 7-9-11 of D-11)
For the E-7b5, the triads are coming from the 7th chord and extended chord tones:
E-7b5 = E-G-Bb-D (notice the G- triad which is 3-b5-7 of E-7b5)
E-11b5 = E-G-Bb-D-F#-A (notice the D triad is the 7-9-11 of E-11b5)
For the A7, the triads annotated on the lead sheet are the upper structure triads of the chord.
F triad over A7 = A7#5#9 (major triad built from the #5)
Eb triad over A7 = A7b9#11 (major triad built from the #11)
On a related note, I highly recommend to learn and memorise the following 4 UST formulas. These are the most common UST shapes and knowing these formulas will greatly speed up your ability to choose and analyse triads for altered dominant chords:
Perhaps you can try to complete this kind of analysis for some of the other chords in the form as a warm up for the seminar.
I’d recommend to pick one of major 251s and one of the minor 251s and write out the notes of the 7th, 9th, 11th, 13th chords, as well as the 4 UST options for the V7 chord.
It’s worth noting that the triad options for the dominant V7 chords don’t have to be USTs, for example you will see a C7 in bar 10 with a G-triad (5-7-9 of C7). This C7 is part of a major 251 in F major, and as we know, alterations are optional for the V7 chords in major 251s.
On the other side of the coin, remember that when dealing with minor 251s, the V7 chord is usually played as an altered V7 chord, in which case the USTs could be more appropriate choices to access the altered tones.