Ibn Ezra on Isaiah
Where our fathers praised Thee through the mouth of the Levites, the singers.19I. E. takes the verb הללוך literally: to praise, i.e., by singing, and this was done in the temple by the Levites. In a more general sense it is paraphrased in Targum Jonathan: דפלחו קדמך אבהתנא where our ancestors worshipped Thee.