Having been in Cubs and Scouts (or more accurately Wolf Cubs and Boy Scouts, in those days) I joind the Army Cadets and there the songs were sung in the back of a 'three-tonner' (lorry) rather than around camp fires, but the effect was the same, songs (albeit generally bawdier than those of the Scout camp) were learned as part of an oral tradition, picked up from earlier members, from fathers, uncles and elder brothers who had served in the Army(the last conscripts been had demobbed only few years earlier) and from older cadets were learned, sung, twisted, adapted and passed on to newer cadets.
To return to Scouting. I don't remember ever seeing a Scout songbook (I suppose there must have been one), every scouting song I learned was by oral tradition - strangely enough, even now, the occasional snatch of tune or round from Scout camp pops into my head for no apparent reason.