Abstract
The subject of the article is Bach’s motet Tilge, Höchster (1746/47) based on composition by Pergolesi. The
degree of involvement of Bach’s copyist J. C. Altnickol in the motet’s invention is attempted. Latin sequence
and German paraphrase of 51 (50) Psalm are analytically compared: the hypothesis that new libretto was
written upon Bach’s own initiative is argued. Influence of the new text both on work’s dramaturgy and vocal
parts’ intonations is considered in detail. Finally, the article contains examples of Bach’s musical arrangement
wherein the aspects of Pergolesi’s musical style are remarkably modified..