You might find this book useful:

"Cohen, David and Ben Greenwood, The Buskers: A History of Street Entertainment, David & Charles, Newton Abbot, England, 1981 The definitive book on contemporary England street entertainers and "Buskers." Traces the history of busking from the Roman era. The two highlights in this book are:
the extensive buskers and street performers interviewed by Henry Mayhew in the 1860s (see the next book)
the authors own interviews of street performers in the 1970s most notably Don Partridge and Alan Young (Alan Young became the philosophical voice of this book. I will include quotes and excerpts in the future)"