The Kalamazoo Department of Public Safety report that a preliminary autopsy indicates that the cause of death was a heart attack, according to the Battle Creek Enquirer. 

Hatfield and his partner Bill Medley were considered the godfathers of �blue-eyed� soul with their group The Righteous Brothers. The duo began performing together in a 5 piece band in Orange County California in 1962 under the name of The Paramours. As legend has it, the duo began playing nightclubs frequented by Marines and one night when a black serviceman heard the combination of Medley�s low smoky baritone and Hatfield�s smooth tenor and falsetto, the Marine cheered the group by shouting "That was righteous, brothers." And the name stuck. 

During the five years they worked together in the 60�s, the duo recorded some of the most cherish songs in rock history. It was their paring with producer Phil Spector that produced the group�s breakout hit �You�ve Lost That Loving Feeling�. More hits were to come; "Just Once in My Life," "Unchained Melody," "Ebb Tide" and the group�s second number one hit "(You're My) Soul and Inspiration." 

Even after the duo broke up, Hollywood had a way of bringing their signature songs back on to the charts for a new generation. �Top Gun� featured a memorable scene where Tom Cruise serenaded Kelly McGillis with a bar room rendition of �You�ve Lost That Loving Feeling�. In 1990 when Hatfield and Medley re-recorded their classic �Unchained Melody� the song not only became a big hit but also earned the duo a Grammy nomination.

In 1999 BMI named 'You've Lost That Loving Feeling' the greatest song of the century since they found it was the most played song of all time on radio and television in the USA. 

Hatfield has recently reunited with Medley and they were to begin a short concert tour Wednesday night with the scheduled appearnace at Miller Auditorium. 

Robert Lee Hatfield was born August 10, 1940, in Beaver Dam, Wisconsin. When he was 4 his family relocated to Anaheim, California. He took an early interest in music and by the time he reached high school he was organizing singing and instrumental groups. 

Hatfield�s other love was baseball and contemplated following that dream as a pro-player before he decided that music was where his heart really was. 

The Righteous Brothers were honored earlier this year when they were inducted into the Rock and Roll Hall of Fame. 

Preview and purchase music from Righteous Brothers