The melodica is a fun instrument with an interesting history.  It began when Mathias Hohner, a German musician and instrument inventor, traveled to Japan.  He heard the mouth organ called the "sho" and believed that he could improve on the design.  Through a series of trial and error, he was wildly successful.  He brought us the harmonica and the accordion.  Improvements and modifications were made in Japan, and Hohner, not to be outdone also invented the melodica.

The melodica is very useful for a number of different applications.  In Asia it is very common as a child's classroom instrument, especially for teaching basic keyboard skills and music theory.  It is popular in Jazz.  It is a novelty instrument for pianists.  Because it is lightweight, portable and affordable, it is especially useful for teaching children keyboarding skills.  The best part?  No batteries!

This brings us to the second aspect of the melodica, which is that it is a member of the reed family.  The volume and articulation can be controlled by the mouth, although better articulation can be achieved with the fingers on the keys.  It takes a lot of breath support to play long phrases.  It takes more air to play louder.  Gaining experience and practice with these skills will set the stage for learning other wind (and brass) instruments as the child advances in music.  So there really are a lot of useful applications for music educators.