It’s the time of the year for family celebrations…and few artists have had the kind of multi-generational family success as Pat Boone.  One of the top ten biggest-selling singles artists in the history of twentieth century pop, Boone was the youngest performer to host a national television primetime variety show with his 1957 program Pat Boone’s Chevy Showroom, and he went on to become a familiar, welcoming presence on the small screen over the ensuing decades.  Family has always been a cornerstone of Boone’s life, and by the 1970s, he, his wife…