Watch your phrasing! The word "targeted" in your subject line and the phrase "make fun out of" make your post seem to be offensive, at least to American ears.
Assuming your post was NOT anti-Jewish, the answer to your question is that Irving Berlin was probably the first, starting around 1910, with a series of songs he wrote for Jewish-dialect comedians, like the young Fanny Brice, with titles like "Yiddisha Nightingale," "Becky Is Back in De Ballet," "Jake! Jake! De Yiddisha Ball Player," and the classic "Sadie Salome, Go Home!"
In this clip from the 1936 movie The Great Ziegfeld, Fanny Brice sings the 1910 "Yidl, With Your Fiddle, Play Some Ragtime":
http://youtu.be/NTwq_Fxr5ak Here's an interesting page on "Sadie Salome":
http://sadiesalome.com/about.html?KeepThis=true&TB_iframe=true&height=600&width=800
Updated On: 11/27/11 at 09:08 PM