This one is silly in its outline - aging rockstar attracted to headmistress his age - but sly in the mechanics; she's boondoggled into keeping a layabout but beautiful niece, the rockstar comes by in pursuit of the niece, niece is so surpassingly irritating and bad-mannered that the charms of the headmistress are shown off.
There's also a mystery plot, but even that has a lot more to do with Who
should date Who than not.
So wrote clew in
Mystery.