Mark Osipovich Reizen, also Reisen or Reyzen (Russian: Марк Осипович Рейзен, born in Zaitsevo village, Ekaterinoslav province, Russian Empire (now Ukraine) 3 July [O.S. 21 June] 1895 – died November 25, 1992 Moscow, Russia) was a leading Soviet opera singer with a beautiful and expansive bass voice.