I made a jamming video with help from SonicVisualiser, it scrolls the chord names and diagrams as the song progresses. I show the chord roman numerals too, the catch being that sometimes I show all three but sometimes only one ...which helps with the learning. Pretty clear so long as standard chords with their numerals are used but here comes a question:
In C#m the C#m chord is the "i" numeral, but what if the piece has a C# major in it? It seems to me that that is no longer the "i" chord and the dilemma (for me at this point at least) deepens when the my video seeks to challenge the subject to play the "i" chord in which case no one could be expected to play a C#.
Rephrased, how to use roman numerals to label off-standard chords and how to come up with the correct chord when seeing such labels?