McGrath of Harlow, thanks for posting that link. The newspaper says that "Whites were not allowed because all the performers were Black."
We'll probably never know, but I wonder whose decision it was that non-Blacks couldn't attend the party-the performers {attendees} or the White in power then?

s&r, and thanks to you also. When I first read your post I wondered what the R&B group the Spinners had to do with Black folk traditions in Britain. The R&B group, The Spinners, are known for such soul classics as "Then Came You," "Games People Play," "The Rubberband Man." and "Could It Be I'm Fallin in Love." My confusion about the two groups is an example of how experiences can shape expectations.
I'm glad to learn about the UK Spinners group.

Also s&r, I've heard that there's a huge carnival in Brixton every year. Are there are other carnivals there or elsewhere in Britain?

When I wrote my initial post I was wondering about the contribution of pre-20th century people of African descent to British folk music. Though I didn't include this, I also wonder if elements of American & Caribbean "soul music" show up in contemporary Black British music. A list of those elements are the use of call & response, improvisation, emphasis on the beat as opposed to the lyrics; preference for falsetto & gritty voices, the use of instruments to imitate the human voice, and preference for blurred or dirty tones in vocal and instruments...

However, just because call & response for example is found in old British vocal music, that does not mean it comes from Black Briton's influence...This afternoon I read through John Storm Roberts' "Black Music of Two Worlds, African, Caribbean, Latin, and African American Traditions' {New York, Simon & Schuster Macmillian, 2nd edition, 1998} and found this interesting passage about the use of call & response in European music:

"Though call & response singing was more coomon in Europe at one time than it os now {some scholars see it as linked to tribal and communal ways of living}m by the tume African and European music met in the New World it had survived in European usage only in a few forms,such as church litanies and ballad refrains. European folk music's ,ost typical tfeatures, the division into regular "verses", came from the equally tupical tendency of European poetry to be divided into regualr groups of lines, most often two, four, or eight. The musical form tended to follow the poetic divisions, so that most songs-unlike songs in the call-and-response pattern-were series of neat packages of four, six, eight, or twelve lines, separated byy pauses or joined by a bit of instrumental filling-in." {p. xxx}

end of quote

It's been interesting reading all of the posts in this thread. I very much appreciate all "appropriate" responses to my original post and certainly welcome more responses!