At its origins during the 1960s, the quartet of male voices making up the Oak Ridge Boys sang four-part harmonies and gospel music. The group switched to country music a few years later and their popularity soared. During the next three decades, the Oaks, consisting of Richard Sterban, Joe Bonsall, Duane Allen, and William Lee Golden, recorded dozens of musical hits, including Bobbie Sue, Dream On, Thank God for Kids, American Made, and Elvira. They have picked up multiple Country Music Association, Grammy, Dove, and other musical awards. The Oak Ridge Boys work more than 150 personal appearances each year. They have entertained dignitaries in Belgium, Canada, England, Finland, France, Monaco, Norway, Soviet Union, Sweden, Switzerland, West Germany. Closer to home, they have sung for several United States presidents. But The Oak Ridge Boys are not just about the accolades. They have also contributed to various philanthropic activities, such as Habitat for Humanity, National Committee for Prevention of Child Abuse (now Prevent Child Abuse America) and Boy Scouts of America. As part of their work with the international relief organization Feed the Children, they have helped collect an estimated three million pounds of food for the needy. Today, The Oak Ridge Boys are still entertaining huge crowds. They will appear at the Embassy Theatre for a Christmas show on Tuesday, Dec. 20, 7:30 p.m. As well as singing holiday favorites, the Oaks will honor their mega-hit song, Elvira, as it celebrates 30 years of recording by the Oaks. If you long to hear some powerfully deep bass notes from Richard Sterban as he croons ‘oom papa maw maw’, get your tickets now. Tickets: $46.25, $38.75 & $29.75. Credit card fees apply. On sale at the Embassy box office, all other Ticketmaster locations and online at Ticketmaster.com.