defaultBarType

[TS Sunhede Fulk]

Hey everyone,

I'm trying to typeset a 17th-century madrigal that uses dotted 
barlines. I would like to change the defaultBarType. I tried

\set Staff.defaultBarType = #":"

But that didn't change anything (no error message either).
I cannot find the correct syntax in the manual or in the mailing-list 
archives.

Can someone help me out?

Thanks in advance,
Ted S. Sunhede Fulk