Counting specific self-portal records

[Clayton King]

It's been a while since I developed a performance/singer set list application in FM18 and am revisiting it. I don't work in FM enough make my desired changes on my own, so asking for some help or directions.

Essentially I have several related tables that grab info into a join (Gigs~Songs_Join) table. Tables include:
Gigs: Date/time, venue, producer, etc. I
Songbook: song title, duration, keys, genre, lyrics, etc.
Musicians: used in Songbook to include original artist, lyricist, composer, etc.
Venues: address, contact for venue, etc., used in Gigs above

The attached snapshot is of the existing layout. 

When this was originally created, there were just two of us performing, so I had a Singer value list created which included Clayton, Vicky and duet (both of us). The "Set List Summary & Counts" section of the layout (circled) is done with summary counts and the headings (Set, Songs, Duration, Clayton, Vicky, Duet) are just text on the layout. Each row in the section is a portal to the same layout (Gigs~Songs_Join) filtered for the Set number at the bottom. The assumption is that a max of 4 sets would be performed, thus four rows. The bottom row in the section shows how many sets, songs, duration, and counts of songs by singer.

We now have additional singers, so I'd like the section to be more dynamic to account for multiple people. Recognizing a practical limit of how big this section can be, and assuming there never to be more than four singers, I'd like to heading in the section to be dynamically created and provide the same info as currently displayed. I edited the Singer value list to include various combinations of people and realized that's not going to work for my goal.

I think what I want is some kind of dynamic field(s) to populate the header row. In the case of duets (i.e., Clayton & Vicky), rather than show that as a duet for the purpose of the summary section, I'd like to increment Clayton and Vicky's counts. So if Clayton sings 3 songs, Vicky sings 4 songs, and they sing 3 duets together, Clayton's count would be 6 and Vicky's count would be 7. The Duet column would go away. Also, if Lanny and Ella perform in a gig, they would (dynamically) appear in the section, with solo and duet counts handled the same way.

I hope this is clear enough to provide some background, and appreciate any help given!