Regardless of how it’s implemented at a user level, conceptually there are two common semantic uses of chord symbols. One is an indication of the prevailing harmony in a bar of music. For instance a chord symbol over a bar of stemless slashes, or a chord symbol over the melody line in a lead sheet. This use case is clearly what Dorico currently handles. The other use case is as an abbreviation. For example, a guitar or piano part with a rhythm notated with slash notheads, where each note has a chord symbol over it. As an abbreviation, the symbols are not global entities, but entirely local to the individual part. This case Dorico does not yet capture. And, of course, the two could occur together as in the attached example. The piano is told to improvise over a prevailing Eb harmony while the guitar has a specific rhythm to play.
