Michigan City Blue by Jeff Lovell
When a bullying thug accosts professional musician Carson Coughlin, threatening him to stay away from a woman, he has no idea that the woman is a person with whom he fell in love with years ago. The two people, crushed emotionally by failed marriages, soon meet and learn that they can build a life together. Lauren, a genius at organization, hires Carson to put together a band to play at a new community center, and, as the center comes together, they face violent retribution from her ex-husband.
Her ex-husband, Richard, faces grim retribution from a crime syndicate, to whom he owes a gambling debt far beyond his ability. After threats, he kidnaps Lauren aboard a tramp steamer, intending to hold her for ransom. A former Navy officer, Lauren manages a daring escape.
Next, Richard kidnaps one of her grandchildren, who Carson manages to rescue from the trunk of a car.
Richard turns to vandalism, hiring criminals to destroy the Center with Arson. The arsonists are apprehended but are unable to help the police locate Richard.
Lauren's daughter and granddaughter are soon victimized, but they learn that they have a long-hidden ability which allows them to escape. Meanwhile, Lauren opens the Center, which is a huge success, and Carson's band is warmly received by the community. After another failed extortion attempt, Richard attempts to kidnap Lauren, but a wild chase into the Dunes National Lakeshore Park results in Richard being trapped in a natural sinkhole in the Dunes.
Richard, bitter and vengeful, is sent to prison in the west.
Many years later, Lauren dies, and her granddaughter becomes a skilled performer. The book ends as Carson, sits waiting to perform at the Center named for his wife and commemorating her gifts and love for the Community. As Carson sits in his office practicing for his next performance, his wife comes to call him to another life at her side.