Dies Irae - Scott Drayco Mystery Series, #3

A mysterious music puzzle.  A murdered coed. Sinister secrets. Three years ago, Scott Drayco left the FBI after an incident involving his partner, Mark "Sarg" Sargosian. Now a freelance crime consultant, Drayco often helps law enforcement on cases, but he never imagined his estranged former partner would turn up on his doorstep, pleading for Drayco's help. A co-ed at an elite Washington, D. C., private college has been murdered, and the victim's friend - Sarg's own daughter Tara - might be the next target. The killer left behind a puzzling music code at the crime scene, and Drayco soon learns he has two things in common with the murdered girl - a music background and synesthesia.
The case takes an even stranger turn after a second murder and a second music code, with signs pointing toward a possible ritualistic killing. Then, Drayco himself starts receiving coded messages .