court and spark, the idiom njc

[Wally Kairuz]

i may be talking rubbish here [as usual] but i'm almost sure that court and
spark is something Shakespearean, it's in one of his plays or something,
like when you say ''by the picking of my thumbs''.
any eng lit majors out there?
and i'm sure there's an interview somewhere in which joni discusses the
origin of the title.
wallyK