The Quibbling Quartet

The New Caldonia Quartet always had problems getting along with each other. Arguments over what music to play, how to interpret it, who should get the most center stage time, even what costumes to wear plagued them ever since the four members came together to form the group. At an attempt at a friendly meeting of some of the members of the group, Paula Gurley, a friend of the talented viola player Suzanne Cousins, dies. The group finds itself under intense scrutiny. When the police come and arrest Suzanne Cousins, it looks like the group will split up.
Detective Cynthia Pierson needs MacFarland's help. She knows Paula Gurley's mother, and wants the case solved. But, she doesn't think the detective assigned to investigate the case will do a good job.
At first MacFarland is resistant. But, when he learns that the man who messed up the evidence chain of custody in his wife's death has been assigned to this case, he has all the reason he needs to look into Paula Gurley's death.
Besides, it gives him a chance to work with Detective Pierson. The only obstacle is the Quibbling Quartet itself. It's members don't seem to be cooperative. What do they have to hide?