וּמַתִּתְיָ֣הוּ וֶאֱלִֽיפְלֵ֗הוּ וּמִקְנֵיָ֙הוּ֙ וְעֹבֵ֣ד אֱדֹ֔ם וִֽיעִיאֵ֖ל וַעֲזַזְיָ֑הוּ בְּכִנֹּר֥וֹת עַל־הַשְּׁמִינִ֖ית לְנַצֵּֽחַ׃
Rashi on I Chronicles
And Mattithiah and Eliphelehu, etc. with harps on the sheminith to conduct those musical instruments upon which they play the psalms entitled: “For the conductor, on the sheminith.”