Could one create a package that invokes lilypond (an external command) and embeds the result?

[SillyFreak]

This recent answer may interest you:

How to call external applications?

There has been extensive discussion about this in the past, but this functionality (often referred to as “shell escape” in reference to LaTeX’s equivalent functionality) unfortunately isn’t really compatible with several of Typst’s aspects, including portability (being able to compile the same document in different environments), purity (function calls in Typst must always produce the same result to make memoization possible), security (compiling a Typst document must not produce unexpected side…