Some of Sweelinck's innovations were of profound musical importance, including the fugue—he was the first to write an organ fugue which began simply, with one subject, successively adding texture and complexity until a final climax and resolution, an idea which was perfected at the end of the Baroque era by Bach.
Nogle af Sweelincks nyskabelser var af dyb musikalsk betydning, herunder fugaen - han var den første til at skrive en orgelfuga, der simpelthen med et emne begyndte at tilføje tekstur og kompleksitet til en endelig klimaks og opløsning, en ide, der blev perfektioneret ved slutningen af ​​den barokke æra af Bach.