I went to Neil Diamond's personal website
http://www.neildiamond.com/popup-f.html
and went to the "timeline" section, which gives this information for
the period 1941-1950:
January 24, 1941
Neil Leslie Diamond
"Neil Leslie Diamond is born in Brooklyn, New York at the Isreal Zion
Hospital, to Akeeba and Rose Diamond."
So it would appear that the famous singer-songwriter Neil Diamond is
no relation to the famous harmonica plyer Leo Diamond.
(Trying to do a search on Leo Diamond bography is complicated by the
existence of a well-known composer named David Diamond who happens to
be David *Leo Diamond, and from a type of gem known as a Leo Diamond.)
Winslow