Rhinestone Cowboy -- Southern Nights --  his 1981 scandalous relationship with a then young country singer named Tanya Tucker.

If you’re of a certain age --- you know who Glen Campbell is.

The legendary country singer/songwriter granted ABC’s Nightline his first TV interview since revealing in June that he is battling Alzheimer’s disease.

Peter Falk set up a trust years before he was formally diagnosed with Alzheimers disease, and the bulk of his multi-million dollar estate is being left to his devoted loving wife of more than thirty three years, RadarOnline.com is exclusively reporting.

The Columbo star passed away at his home in Beverly Hills on Thursday night, and his wife was at his side when he died.

Falk's estate is estimated to be worth around five million dollars, a source close to the situation tells us. "Peter left the bulk of his estate to Shera. The house that the two of them lived in together, art work, investment accounts, and more have been left to Shera. Peter also left an estimated six figure inheritance to his two adopted daughters from his first marriage.