Hi Stine,

> <opener>To the tune of <title>Let it Be</title> (the Beatles)</opener>

You might just add an indication that your opener-element
specifies the tune to which the song should be sung. I would use
the opener's ana-attribute, pointing to an interp-element with
type-attribute 'tune'. This would facilitate eg. generating a
tune index.

It's the approach I've been generally using when I wanted to add
some kind of classification to elements which don't carry a
type-attribute themselves.

If anyone with more encoding experience than I have cares to
comment on this, please, go ahead.

Regards,
Peter Boot