DuckCorp Dico

Found one definition

1.                 From Japanese-English FreeDict Dictionary ver. 0.1:
                   
   
   
                   
                     
   律旋 /(en)tʃˈaɪniːz(ja)lˈe̞tə (en)tʃˈaɪniːz(ja)lˈe̞tə/, りっせん /ɽˈisse̞ɴ/
   (noun (common) (futsuumeishi))
   呂旋Japanese seven-tone gagaku scale (corresponding to: re, mi, fa, so, la, ti, do, i.e. the Dorian mode)