Also worth mention in this thread:

The Mauthausen Cantata. This is four poems by Iakovos Kambanellis (in Greek, I assume), set to music by Mikis Theodorakis. The premier performance was by Maria Farantouri in 1965. Her performance of one of the four songs, called The Song of Songs, appears on the CD, The Fig Tree, a musical companion to Arnold Zable's book of the same name. The CD is on the Boite label, www.boite.asn.au I don't know whether the full Farantouri performance is available.

Emma Schaver recorded an album, From the Heart of a People. Side 2 (we're talking vinyl here, folks) is called Songs of the Ghetto, and consists of Ani Maamin, Sleep My Child (Wiglied), Es Brennt, The March of Death (Nirkoda), and Zog Nit Az Du Geist Dem Letzten Veg (Partisanen). Where I give two titles, the first is from the record jacket, the one in parentheses is from the record label. There's no date on the LP, and I don't know whether it has been reissued on CD.