This is being rebroadcast today on Radio 4 Extra, and will be available on IPlayer for the next seven days.

As far as English language folk music content - well, one verse of Where the River Shannon Flows; but some anecdotes of interest to any of us who have ever tried to collect material from source singers. In particular since the POWs found out that the recording musicologists were giving their recordees extra grub and fags they were very keen to be chosen, and inclined to exaggerate what they could do - singing bits of opera and claiming it was folksong, or claiming their Russian songs were actually from Ukraine or Georgia.

Also listen to the wonderful recording of the man singing verses of the Quran and tell me if it doesn't sound awfully like an Irish singer performing in Gaelic a folk song which you just can't quite put your finger on.