Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (70 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.
This link [1] proves it was copyrighted in 1941. Just search the album up.
This link [2] is a search of the U.S. Copyright Office's 1978- records. Nothing was found for this album cover, therefore it's copyright expired before 1978.