Here's one by James Brown, where, on the '45, the B side is a continuation of the A side.
Maybe it's my early days when I went to synagogue on Yom Kippur with my parents, but to me St. Clair Pinckney's tenor sax wailing on side 2 sounds a lot like the way the Cantor would blow the Shofar during the Yom Kippur services...
That was the first JB single that I bought right after buying the first "Live At The Apollo" LP