While the two core novels, Queen City Jazz and Mississippi Blues tell the story of Verity's journey across a ruined America to the fabled Crescent City, Crescent City Rhapsody and Light Music wrap around to tell the story of the mysterious alien signals known as The Silence and the resulting nanotech revolution, and what they both mean for the future of mankind.
The final part of Goonan's story, Light Music is the story of two misfits: one a nanotech engineer who helped build the failed utopia of the flower cities (now convinced he is a radio theatre cowboy), the other a scientist stripped of her enhancements in order to survive outside the city. It's time for Crescent City to fulfil its destiny, and leave for the stars, but a pirate attack has damaged the city's memory - destroying vital navigation information. It's only hope is two damaged people travelling across a damaged country looking for the lost information, their stories intersecting with those of an autistic girl from the Moon and an Argentinian woman looking for her missing son.
Goonan's episodic style works well when dealing with five or six separate storylines, following her character's journeys, guiding the reader through them, teasing us as to how (and if) they'll ever meet. But we know that the ultimate climax will be at Crescent City itself, the siren beacon that has guided us through the story so far - so their journeys and trials serve an ultimate purpose (and may even guide them on paths to personal revelations and redemptions).
It's difficult to summarise the plot of a novel like this without providing spoilers to previous stories - especially as it's clear that Light Music isn't a standalone novel. You'll need to have read the previous three to understand Goonan's complex world - especially as what appear to be supernatural events are leading to mysterious disappearances. There's a big question here: how can humanity cope if forced through the refiners fire of evolutionary change on a short timescale. While her answers may not satisfy every question she's raised, they're good enough to provide a satisfactory conclusion to a lengthy saga.
If you've read the first three novels, you'll need to read this to find out how Goonan wraps everything up at last. If you haven't rush out and track down a copy of Queen City Jazz - possibly the best book to show the after effects of a failed Vingean singularity.
But now she's finally finished her quartet of novels, what will Goonan do next?