Soprano ukuleles are the smallest of the ukulele family, producing a soft and sweet tone. When I think of sopranos, Israel Kamakawiwo'ole's beautiful "somewhere over the rainbow/what a wonderful world" rendition comes to mind, but others maybe Tiny Tim comes to mind. Sopranos are the most common ukulele size for beginners, and those looking for a portable/travel ukulele.
Pono are currently just making the MDS as Pono don't sell too many sopranos. They chose to just make the MDS as it worked best for their design, and was the most popular. This ukulele has a smaller than average body, is super portable and sounds beautiful. This is a great entry-level or beginner ukulele for someone looking to enter the wonderful world of ukuleles playing an all solid wood ukulele.