Yasuhide Ito (b. 1960) is one of Japan’s premier composers of original music for wind band.  He is best known for his 1990 suite for wind band Gloriosawhich is performed frequently all over the world.  He has written several dozen other pieces for band and other media, including symphonies for band and at least one full opera, going back to his first band work, On the March, of 1978, written when he was in his third year of high school.  Ito is also a renowned pianist, conductor, lecturer, and translator.

As you will see below, Ryukuan Fantasy exists in many different versions, all created by Ito himself.  Here are his program notes, as featured in both the score and on the Bravo Music website, from the revised band version of 1998 (not to be confused with the band and piano version of 1999):

Based on the Okinawan Folksong Asadoya Yunta.
Originally sung in a slow cantabile style, this exciting musical arrangement has an energetic rhythmic drive and momentum. The original version is for 2 pianos with 8 hands and was commissioned by the Yo-gen-kai association in March, 1997. It was premiered by the Okinawa Prefectural University of Arts professor Setsuko Iwasaki and her students.

Other arrangements include: 2 pianos for 4 hands, one piano for 4 hands, solo piano, violin and piano, soprano saxophone and piano, piano sextet, saxophone quartet, violin with saxophone quartet and piano, saxophone quintet and piano, saxophone quartet and piano, marimba sextet, and piano and wind orchestra.

The first band version was commissioned and premiered by Toshima-Ku Wind Orchestra conducted by Ito himself. It was featured composition in the January 1999 issue of Band Journal (the popular Japanese wind band monthly by ONGAKU NO TOMO SHA). Later, it was re-commissioned and re-orchestrated for the Hamamatsu Municipal High School Band conducted by Hideki Koshiba. Since the original version was composed for piano, its strongly percussive character must remain.

Here are just a few of those versions.  I am looking at the straight wind band version, which sounds like this:

There is also a version for wind band and piano:

Then there’s the saxophone quartet version:

And the saxophone quintet with piano version:

Here is sort of a contemporary folk-flavored take on the traditional tune:

This other WordPress blog digs deeper into the original tune – it is INDISPENSABLE reading and listening for anyone interested in the way this melody has spread around the world.  This article from The Ohio State University adds further context and history.

More on the composer on Wikipedia, Bravo Music, and his own website.