What does 'B.B.' in B.B. King's name actually stand for ?

The radio spot became so popular that it was expanded and became the Sepia Swing Club. Initially he worked at WDIA as a singer and disc jockey, gaining the nickname "Beale Street Blues Boy", which was later shortened to "Blues Boy" and finally to B.B. and  B.B. King's real name is Riley B. King. He was born in 1925 in Itta Bena, Mississippi, and he moved to Memphis in 1947. His first major radio appearance was in 1948 on the West Memphis .