# `Mx.Instrument.Expr`
[🔗](https://github.com/mx-music/mx/blob/main/lib/mx/instrument/expr.ex#L1)

A value a `defsynth` works out from the note's options: one option, or a call of the vocabulary on its arguments and named arguments.

# `call`

A call of the vocabulary.

# `traced?`

Whether `value` depends on the note.

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*Consult [api-reference.md](api-reference.md) for complete listing*