Song that plays during episodes previews of Hunter x Hunter
According to Glass Reflection's review ( https://youtu.be/VgnSAOSo-Tk?t=10m22s ) and a re-listen to the preview music, it is called The World of Adventures, by Yoshihisa Hirano. I found the whole track: https://www.youtube.com/watch?v=pOBppjlkXGc