Musical chairs a novel

Bridget and Will have the kind of relationship that people envy: they're loving, compatible, and completely devoted to each other. The fact that they're strictly friends seems to get lost on nearly everyone. After all, they're as good as married in (almost) every way. For three decades, they've nurtured their baby, the Forsyth Trio - a chamber group they created as college students - but now their beloved trio is missing its violinist and flounde...