Vocal slurring and override-auto-beam-setting?

[Mike Blackstock]

Not being a singer, I assumed that vocal music never has beams - wrong! 
I see that when notes are slurred, the slurred notes have beams. Is 
there an easy way to indicate that if notes are within a slur, they 
should be beamed, otherwise not?

I suspect it can be done with 'override-auto-beam-setting' but  the 
examples in the manual are making my head spin (especially after having 
spent way too long last night dicking around with sendmail.cf  -  I 
can't handle anything remotely cryptic today).

Thx and cheers,
Mike