He sang of life, serenely sweet,
With, now and then, a deeper note.
From some high peak, nigh yet remote,
He voiced the world's absorbing beat.
He sang of love when earth was young,
And Love, itself, was in his lays.
But, ah, the world, it turned to praise
A jingle in a broken tongue.
People offered praise, but the praise was for music or poems that were perhaps imperfect. 
 The line is often viewed as a larger point from Dunbar that audiences preferred his dialect poems (i.e. in so-called broken English) as opposed to his formal verse.
The Poet