The operation was carried out by the user LeBrickster, who published the music on YouTube at this address and we advise you to listen to them quickly, because knowing Nintendo it is possible that they will be removed soon.
The user in question has carried out the restoration starting from the famous gigantic leak that hit Nintendo with the diffusion of various documents and files belonging to the classic online catalog, including the source code of Super Mario Advance for GBA, which uses samples of the original Super Nintendo soundtrack.
In this case it is a major restoration work: the user in question has in fact discovered or that these samples contained references to the instruments used for the composition of the original Super Mario World music, thus trying to restore the original uncompressed audio quality.
The result should be more faithful to the quality that the tracks should have original audio regardless of the compression performed to be able to enter the memory of the cartridge for Super Nintendo. This can result in a quality that you may or may not like: the author of the original music, Koji Kondo, has probably also kept in mind some memory constraints to study the tracks in order to play at their best in the tiny space available, so it is possible that the shape in which they appear on the cartridge is in any case better.
It is however curious to hear this variation and to think about what Kondo could have done in case he didn't have to deal with the memory constraints caused by the SNES cartridge.
Source