at the end of let robeson sing you hear people clapping. these people are welsh miners clapping for paul robeson after he sang the welsh national anthem for them through telephone in 1952. he wanted to perform live for them, but he could not come to great britain because joseph mccarthy, in his witch-hunt on communists, withdrew his passport In 1950. This act of vindictiveness was universally condemned. in 1958 the u.s. government finally gave him back his passport, to which the line 'no passport 'til 1958' in let robeson sing refers.