?value: root      
    root: (pc | dur_change | oct_mod | oct_change | WS | chord | cycle | random_integer | random_pitch | random_percent | range | list | subdivision)*
    list: "(" root ")"
    random_integer: /\(-?[0-9]+,-?[0-9]+\)/
    range: /-?[0-9]\.\.-?[0-9]/
    cycle: "<" root ">"
    pc: prefix* pitch
    pitch: /-?[0-9TE]/
    random_pitch: "?"
    random_percent: "%"
    prefix: (octave | duration_chars | escaped_decimal | escaped_octave)
    oct_change: escaped_octave WS
    escaped_octave: /<-?[0-9]>/
    oct_mod: octave WS
    octave: /[_^]+/
    chord: pc pc+
    escaped_decimal: "<" decimal ">"
    dur_change: (duration_chars | decimal) WS
    duration_chars: dotted_dur+
    dotted_dur: dchar dot*
    decimal: /-?[0-9]+\.[0-9]+/
    dchar: /[mklpdcwyhnqaefsxtgujzo]/
    dot: "."
    subitems: (pc | WS | chord | cycle | subdivision)*
    subdivision: "[" subitems "]"

    %import common.SIGNED_NUMBER
    %import common.WS