I wrote a song called "The Aberfan Coaltip Tragedy" or just "Aberfan" during the days following the event which was printed in "Broadside Magazine" and the book "Best of Broadside Volume II" and recorded by me on my first Folkways LP in 1968 (still available from the Smithsonian) and included on a 5 CD set "Best of Broadside, 1962-1988," also available from the Smithsonian. The song was also recorded by the Danish folk group Paddy Doyles on their album "Aberfan" which is not, so far as I know, still available. Pete Seeger sang the chorus of this song in London during the British news blackout (they were afraid news of the event might bring down the government). Full lyrics are on my website http://www.geocities.com/parrottsongs/ -- the chorus is

How many died in Aberfan when the coal tip came rumbling down?
How many children will never grow old?
And how many lives purchase how many tons of coal?