Re the timing of "As I roved Out" I am pretty sure that it was earlier on a Sunday Morning, preceding "Family Favourites" which was a long runing record request programme for forces serving overseas.

Regarding the music used I am pretty sure that most of it was "field recordings" made by collectors such as Seamus Ennis, Alan Lomax, maybe Bob Copper and also Jean Ritchie when she was here etc. Although Topic Records had been in existence for a long time I believe the majority of their material was recorded after this series was broadcast. One well known collector the bulk of whose work appeared on the Topic label was in fact inspired in his youth by the BBC coming to record the singing of his grandfather when the collector was in his early teens.
As for whether the programme was mega important or not, it certainly was to me. The chance to hear real music warts and all instead of the pop music of the day was great. It was programmes such as this along with Guitar Club and Jazz club all of which the BBC managed to squeeze into it's schedules at the time that nurtured my lifelong interst in music. This of course was in the days when the Musicians Union was for musicians and needle time was restricted meaning more live music and a much more intelligent presentation of recorded music programmes by the people today known as disc jockeys.

Apologies If I rambled on.

Hoot