Brenda Lee was 13 years old in 1958 when she recorded “Rockin’ Around the Christmas Tree.” Sixty-five years later, it has become a part of the Christmas music catalog, been covered by hundreds of other artists, and remains an iconic part of every Christmas tree lighting and celebration. But it has never reached No. 1 on the Billboard 100 list until this year. At 78 years old, Brenda Lee toppled Mariah Carey from her throne to become the oldest woman to reach this musical milestone.