// Root for the rules    
    ?root: sequence  
    sequence: (pc | dur_change | oct_mod | oct_change | WS | chord | cycle | random_integer | random_pitch | random_percent | range | list | lisp_operation | list_op | subdivision | eval | euclid)*
    
    // Pitch classes
    pc: prefix* pitch
    prefix: (octave | duration_chars | escaped_decimal | escaped_octave)
    pitch: /-?[0-9TE]/
    escaped_decimal: "<" decimal ">"
    escaped_octave: /<-?[0-9]>/
    octave: /[_^]+/
   
    // Chords
    chord: pc pc+
  
    // Valid as integer
    ?number: SIGNED_NUMBER | random_integer

    // List
    list: prefix* "(" sequence ")"

    // Right recursive list operation
    list_op: list (operator (list | number))+
    operator: /([\+\-\*\/%]|<<|>>)/

    euclid: list euclid_operator list?
    ?euclid_operator: /<[0-9]+,[0-9]+(,[0-9])?>/
    
    // TODO: Support randomization etc.
    //euclid_operator: (">" | "<") number "," number ["," number] (">" | "<")
    
    // Lisp like list operation
    lisp_operation:  "(" operator WS sequence ")"
 
    // Durations
    duration_chars: dotted_dur+
    dotted_dur: dchar dot*
    decimal: /-?[0-9]+\.[0-9]+/
    dchar: /[mklpdcwyhnqaefsxtgujzo]/
    dot: "."

    // Subdivision
    subdivision: "[" subitems "]"
    subitems: (pc | WS | chord | cycle | subdivision)*

    // Control characters modifying future events
    oct_mod: octave WS
    oct_change: escaped_octave WS
    dur_change: (duration_chars | decimal) WS

    // Generative rules
    random_integer: /\(-?[0-9]+,-?[0-9]+\)/
    range: /-?[0-9]\.\.-?[0-9]/
    cycle: "<" sequence ">"
    random_pitch: "?"
    random_percent: "%"

    // Rules for evaluating clauses inside {}
    // TODO: Support for parenthesis?
    eval: "{" operation "}"
    operation: atom (operator atom)+  
    atom: (number | DECIMAL)

    %import common.NUMBER
    %import common.SIGNED_NUMBER
    %import common.DECIMAL
    %import common.WS