Chords are being ignored during compilation

[slurmulon]

Problem

The Chord entity seems to be getting ignored during parsing and/or compilation.

Example

In this case, the resulting data field is entirely empty.

Bach

@Tempo = 68

:G = Chord('G3')
:D = Chord('D3')
:A = Chord('A3m')

!Play [
  1 -> :G
  1 -> :D
  2 -> :A
]

Bach.JSON

{
    "data": [],
    "headers": {
        "audio": "",
        "desc": "",
        "link": "",
        "lowest-beat": 1,
        "ms-per-beat": 2000.0,
        "tags": [],
        "tempo": 120,
        "time": [
            4,
            4
        ],
        "title": "Untitled",
        "total-beats": 0
    }
}