Conversation so far:
What was Hound Dog by Big Mama Thornton originally released as
Recorded originally by Big Mama Thornton on August 13, 1952, in Los Angeles and released by Peacock Records in late February 1953, Hound Dog was Thornton's only hit record
What day was Hound Dog by Big Mama Thornton re-released on
As the new sensation Elvis Presley recorded Hound Dog to international acclaim, Peacock re-released Willa Mae Thornton's original by August 18, 1956.

Question: what changed
Self-contained rewrite: what changed between Hound Dog by Big Mama Thornton's release in February 1953 and its re-release on August 18, 1956