[Serafin]

That sounds very specific, triggered by your (very specific) personal requirements.
How about just adding a text file to your setlist to keep this info?

I appreciate your perspective. Perhaps it isn't a common use case in your environment, and we can argue about the common usefulness of some specific fields I suggested, but for working musicians who perform in multiple venues or with multiple groups, I believe that there is a good case to be made for being able to leverage the existing setlist database (the list of setlists) for more than just the list of songs performed or to be performed. It also seems natural to add other database functions to the database that MobileSheets is.

I (and others) will find it useful to run queries and create reports to...

• display set lists that apply to Band A only
  
• display set lists for say previous wedding banquets or wedding ceremonies (songs may come from multiple genres)
  
• report usage occurrences for songs were performed at XYZ church (for royalty reporting purposes)
  
• sort set lists for concerts according to rating (what set lists worked well in the past?)
  
• account for other gig (most setlists represent gigs or events) attributes - personnel, income, etc.
  

There's an existing category of software for managing gig data, but some (most) are overkill for individual musicians or small groups, and I believe that there's a case to be made for leveraging what already exists in MobileSheets.

I do like your idea of using a text file that is attached to the setlist to achieve some of these use cases, but this partial solution wouldn't facilitate queries and reports.