Blitzstein appeared first in a closed session .
Blitzstein admitted his membership in the Communist Party ( ending in 1949 ) and , challenging the right of HUAC to question him at all , refused to name names or cooperate any further .
Appearing first in a closed session , Blitzstein admitted his membership in the Communist Party ( ending in 1949 ) and , challenging the right of HUAC to question him at all , refused to name names or cooperate any further .