Sanpogakuso was an organization for handing down gagaku (Japanese ancient court music and dance), established as a system in the early Edo period and each ho (one office) consisted of 17 musicians and, therefore, sanpogakuso consisted of 51 musicians in total.
三方楽所（さんぽうがくそ）は江戸時代初期に制度化された雅楽の伝承組織で、一方17人ずつ計51人からなる。