Mary Lou Metzger (born November 13, 1950 in Pittsburgh, Pennsylvania) is an American singer and dancer best known as a cast member on The Lawrence Welk Show.The only child of Ernie and Helen Metzger, the family moved to Havertown, Pennsylvania where at the age of seven Metzger officially began her performing career, which included appearances on The Ted Mack Amateur Hour and acting in a national tour of The Music Man by Meredith Willson.While a student at Temple University, she went to Los Angeles, California to appear on the television program GE College Bowl; while there she auditioned for Lawrence Welk and was accepted in the show's apprentice training program.During her twelve years on the show, she sang as part of a female trio with fellow Welk stars Gail Farrell and Sandi Griffiths, various group numbers, and song-and-dance numbers with Jack Imel; she also danced with the maestro himself at the end of each show.