The only reason for these four executions was as a veil for the planned execution of Erskine Childers, on the excuse of his having a gun. Childers was in the house of his Barton cousins in Glendalough when soldiers burst in and screamed at the housekeeper, and he came out of his bedroom upstairs to see what was happening. He was holding a small gun.
The gun had been a present from Michael Collins.
Pat DeVerse, the most likely person to tell you if there are any songs is possibly Erskine Chiders, grandson of the man murdered; he was on Twitter when I used to be there.