As far as I know, padrone isn't a term used in UK, so that might explain why you're not getting much joy there. "Masters" seems to be a better word here.
Putting "street musicians" into Gale for the 1860-1890 period gives about 500 hits, many are comments on the nuisance caused by these musicians. Incidently, I found 2 references to the "celebrated Bosco family" of musicians and instrumentalists in early 1860s, including 2 lads who were violinists. Unfortunately, I haven't found any more info. but I only looked briefly.
Good luck with your search
