The question title says it all.
I can see two ways this can go: either it is on-topic by virtue of text-based DTP or it is not on-topic because it is not based on any TeX engine despite its syntactic similarities (to my knowledge).
The type of question I would ask is how to typeset a specific chord (
<b d' g'>) in chord notation. This question is uncomfortably similar to How to look up a symbol or identify a math symbol or character?, but seems to have more to do with music theory than typesetting.