A minor/major seventh chord is composed using a root/1st, minor 3rd, perfect 5th and major 7th (or R/1-♭3-5-7) intervals played simultaneously. Generally written as Cmi(MA7) or C-(MA7), it is good practice to simply use an uppercase C, the lowercase letters mi followed by super scripted uppercase (MA7) to represent it in writing (ie: Cmi(MA7)).
A minor/major seventh chord occurs naturally in a harmonized harmonic minor scale on the first scale degree (tonic), and although it does not occur naturally in a harmonized major scale, it does appear in a major scales parallel harmonic minor. Remember that interval formulas are always written relative to a major scale.
The tonality of a minor/major seventh chord is heavily dissonant and distinctly unresolved, as opposed to the stability of a major seventh chord.
Minor/major seventh chord profile
|Intervals||root/1st, minor 3rd, perfect 5th, major 7th or R/1-♭3-5-7|
|Stability||Dissonant, unstable, unresolved|
|Common names (examples in C)||Cmi(MA7), C−(ma7)|
Minor/major seventh chord table
|Chord name||Root||Minor third||Perfect fifth||Major seventh|
|A♯mi(MA7)||A♯||C♯||E♯ (F)||G (A)|
|C Minor/major seventh chord voicing #2|