I guy I know has the first name of UB. I asked him if his first name was Ulysses. He said no and that UB stood for Unknown Boy. He told me the story about his great-grandfather who was a slave in the south and it was fairly common at that time that black boys and girls who were split from their families and sold to another slave owner didn't come with their birth names and the owners simply wrote their names down as UB or UG. His great-grandfather's name was passed down to the UB I know.
Lyrics by William Chatterton Dix "What Child Is This?" set to the tune of "Greensleeves" written in 1580 possibly by King Henry VIII. Performed by the Moody Blues.