On Tuesday - folk club night - Ginny and I were talking about when we'd first heard folk songs.
The first I heard in the outside world was probably Steeleye Span's version of All Around My Hat (released in 1975, I see). In my home world, Gaelic songs were always around me from earliest times, and also Scottish and Irish folk - I certainly knew of The Corries in primary school (including the fact that we had a tape of theirs), and for some reason The Clancy Brothers with Tommy Makem stick in my mind - someone must have had their record.
In primary school, as well as learning gaelic songs for the Mod in choirs and action songs (little plays featuring two or three songs, all in Gaelic), for music we sang from one particular songbook which I remembered as being mainly folk songs from the British Isles and America, a small blue book, I thought, possibly called The Oxford Songbook.
My mother confirmed that it was indeed The Oxford Song Book, and pointed me to it here online. The first few pages of the PDF are blank, but it does start to appear, with the alphabetical table of contents coming in at p17, and my goodness, it is indeed quite a collection. My childhood comes swimming up before me.