this from
http://open-site.org/Arts/Music/Composition/Co mposers/Gershwin,_George/Childhood_and_Ancestr y/
They were in residence at a two-story Brooklyn brick house in a Jewish suburb, at the address 242 Snedicker Avenue, when Jacob Gershovitz was delivered into the world by a Dr Ratner, who remembered Morris as a �leather worker� and Rose as �Rosa Brushkin.�
The change of name form Gershovitz to Gershwin was somewhat of a complex matter to explain; �it is possible that by the time he (Morris) married he had streamlined his name to Gershwin� (Jablonski, 1987), and it is also a mystery how George Gershwin was never named Jacob or Jake, yet registered on his birth certificate as Jacob Gershwin. Many sources I researched in preparation for compiling this report informed me that �George Gershwin� was infact the American alternative to �Jacob Gershovitz.� This causes the truth to be concealed, but I would suggest an errror in the birth registry, and Morris�s change of surname simply a shortened Jewish version of the original name.
George Gershwin was named in memory of his grandfather; this would mean that Yahov Gershovitz, the artistic talent of one of the greatest people in American musical history, had already died.