Understanding how LilyPond handles external fonts

[Urs Liska]

Hello list,

I have some difficulties understanding how to access the different versions/weights/styles of external fonts (in markups mode). And I'm not sure if this is a LilyPond or rather a documentation issue.
So before submitting a documentation suggestion I'd like to really understand the issue.

I understand that I have to override the font-name property to access external fonts.
For example
    \override TextScript #'font-name = #"Arial"
or
    \markup { \override #'(font-name . "Arial") ... }

What I'm not really clear about is how LilyPond accesses the different variations of the fonts.

It seems that overriding font-series doesn't have an effect at all.
Instead I seem to have to specify the full font-name
So
    \markup { \override #'(font-name . "Arial") \override #'(font-series . bold) }
doesn't work, while
    \markup { \override #'(font-name . "Arial Bold") ... }
does.

So if this is true (and not considered as a bug) I think there would be the need for a documentation improvement.

To understand this topic I have another question: What is the correct form of the font-name that has to be specified? Where does LilyPond look at?

I have a font family installed which has a great variety of fonts, lets call it Minion Pro.
Let's say I want to use the Medium Condensed version, then how should I know what name to use here?

In Scribus it is called "Medium Cond",
in OpenOffice "Med Cond",
Fontmatrix gives me
- "Medium Cond"
- Postscript name "MediumCn"

Nowhere I find "Medium Condensed", but this is the only one that works with LilyPond.

Any ideas?

Best
Urs