Semi-globally changing fonts

[Bertalan Fodor]

Hello,

I'm working on a songbook and must use ae fonts instead of cm. That 
means in lyrics I can easily tell in a common paper block:
\LyricsContext \override LyricText font-name = #"aeb10"

However, using the same for TextScripts is not fine, because there are 
many style of them (italic, bold, plain). (And this can occur for Lyrics 
texts as well, but not so often.) So I must define a font for italic, 
bold, etc.

So how can I redefine the settings in font.scm in my common paper block? 
I tried including the same in a Scheme block but that didn't work.

Thank you,

Bert