Function substitute_minor_for_major

mingus/core/progressions.py:293–326

Substitute minor chords for its major equivalent. 'm' and 'm7' suffixes recognized, and ['II', 'III', 'VI'] if there is no suffix. Examples: >>> substitute_minor_for_major(['VI'], 0) ['I'] >>> substitute_minor_for_major(['Vm'], 0) ['bVIIM'] >>> substitute_minor_for_

(progression, substitute_index, ignore_suffix=False)

def substitute_minor_for_major(progression, substitute_index, ignore_suffix=False):
    """Substitute minor chords for its major equivalent.

    'm' and 'm7' suffixes recognized, and ['II', 'III', 'VI'] if there is no
    suffix.

    Examples:
    >>> substitute_minor_for_major(['VI'], 0)
    ['I']
    >>> substitute_minor_for_major(['Vm'], 0)
    ['bVIIM']
    >>> substitute_minor_for_major(['VIm7'], 0)
    ['IM7']
    """
    (roman, acc, suff) = parse_string(progression[substitute_index])
    res = []

    # Minor to major substitution
    if (
        suff == "m"
        or suff == "m7"
        or suff == ""
        and roman in ["II", "III", "VI"]
        or ignore_suffix
    ):
        n = skip(roman, 2)
        a = interval_diff(roman, n, 3) + acc
        if suff == "m" or ignore_suffix:
            res.append(tuple_to_string((n, a, "M")))
        elif suff == "m7" or ignore_suffix:
            res.append(tuple_to_string((n, a, "M7")))
        elif suff == "" or ignore_suffix:
            res.append(tuple_to_string((n, a, "")))
    return res


def substitute_major_for_minor(progression, substitute_index, ignore_suffix=False):