Yes, Reaper don't get all the musicxml chords on import at the moment:
https://forum.cockos.com/showthread.php?t=209607
You can make a script to rename Notation Events Chord names in the Midi Editor to however you like.
This is a section from one on the scripts in ReaTrak
https://forum.cockos.com/showthread.php?t=212645
You have a list of alias names and set the default to what you want:
full_name = Cm-5 -- current notation event name
root_name, chord_name = string.match(full_name, "(%w[#b]?)(.*)$")
if string.find(",dim,m-5,mb5,m(b5),0,", ","..chord_name..",", 1, true) then new_chord_name = dim
So results in:
root_name = C
chord_name = m-5
new_chord_name = dim
new_full_name = Cdim
Some of the symbols used for chord quality are similar to those used for
interval quality:
- No symbol, or sometimes M or Maj (see rule 2 below) for major,
- m, or min for minor,
- aug for augmented,
- dim for diminished.
In addition, however,
- Δ is sometimes used for major,**[a] instead of the standard M, or maj,
- − is sometimes used for minor, instead of the standard m or min,
- a lowercase root note is sometimes used for minor, e.g. c instead of Cm,
- +, or aug, is used for augmented (A is not used),
- o, °, dim, is used for diminished (d is not used),
- ø, or Ø is used for half diminished,
- dom may occasionally be used for dominant.
**The symbol Δ is ambiguous, as it is used by some as a synonym for M (e.g., CΔ = CM and CΔ7 = CM7), and by others as a synonym of M7 (e.g., CΔ = CM7)
.