The Other Family by Joanna Trollope

When once-popular pianist Richie Rossiter unexpectedly dies, he leaves his family behind to pick up the pieces. Chrissie, his partner of 23 years, feels sorrow that Richie never married her and wonders how she'll support their daughters, Tamsin, Dilly, and Amy, since she was his manager. Richie also never divorced his wife, Margaret, even though he had no contact with her or their son, Scott, after leaving Margaret for Chrissie. Soon, the two families are forced to confront their emotions towards each other when Richie's will is read. How will everyone learn to put the past behind them and move forward?