Street singing was ommon in Britain and Ireland - it still is - they call it buskig nowadays
I used to drink in a pub in London which displayed a reproduction warning notice listing the horrific punishment meted out to 'singing beggars'
Harry Cox's 'German Musicianer' is a bawdy comic song, probably originating on the stage - Steve will tell you - 'romantic', but not in the way you mean!
Cox's 'musicianer' is an instrument mender rather than a performer - thre are also related songs that make him a watch or clock mender

I believe the 'profession' street singers (legal ot illegal) whod did nothing else were largely a feature of the Towns - those in Ireland did whatever work they could lay their hands on
We recorded a Traveller in Ireland, Mikeen McCarthy, from Kerry, who sand at the fairs and markets in rural Ireland in the 1940s and '50s - we got more songs, stories, lore and information from him then we did from anybody else (apart from Walter Pardon)
He described in some detal the process of taking his fathers traditional songs into a local printer, reciting them over the counter and having them turned into 'ballads' (the term used for the song-sheets that were sold all over Ireland)
There's a hilarious description of him trying to teach the tune to an American customer in Listowel on the double CD of Traveller recordings we issued, 'From Puck to Applby'
Mikeen's experiences are a clear example of traditional songs being given to printers in order to sell them.
Mikeen, like all the singers we interviewed, were clear dividing their singing into their different functions - those for street singing and selling on 'the ballads' covered the lot, from traditional to the popular songs of the day, those sung in the pubs were called 'come-all-ye's", and the traditional songs sung in a traditional manner he called 'fireside songs'
Irish radio made a magnificent three-part series of our recordings and interviews with us of our work with travellers, called 'Come All You Loyal Travellers' (one of the best displays of our work) I feel
WE have a recording of our interview with Mikeen, to our producer friend, as he listed all the jobs he had done on the road, from tinsmithing and horse-dealing right though chairmaking, general carpentry, selling holy pictures... to clearing rubbish from empty houses.
The list took nearly five minutes to get through - Paula had to fade it after less than a minute - she based an entire programme just on Mikeen.
Singing and selling was only a tiny fraction of his work
He was not just an 'informant' - he became a lifelong friend up to his death in 2005

I know that street singing was an occupation elsewhere in Europe - I once attended a memorable talk by Belgian collector, Stefen Topp on one of his street singers, Alfred(?) Geens

Walter pardon of Norfolk mentioned an Italian peddler who used to come around his art of rural Norfolk who sang in the streets

My point was that oral influences were far more likely to have been the reason why our folk motifs are international than literary ones (in a non-literate Britain)
Jim