From Japanese-English FreeDict Dictionary ver. 0.1: シ /ɕˈi/, チ /tɕˈi/ (noun (common) (futsuumeishi)) ti, si, 7th note in the tonic solfa representation of the diatonic scale
シ /ɕˈi/, チ /tɕˈi/ (noun (common) (futsuumeishi)) ti, si, 7th note in the tonic solfa representation of the diatonic scale