Use of the term "shanty", once this paradigm for singing had become a comprehensive practice for most tasks, incorporated all manner of shipboard work songs under its definition, regardless of style and origin. Yet, shanties were of several types, and not all had necessarily developed at the same time. "Capstan shanties", some of which may have developed out of the earlier capstan songs discussed above, are quite variable in their form and origins. On the other hand, the repertoire of the so-called "halyard shanties" coheres into a consistent form. The distinctive "double-pull" format that typifies most of these songs—also at times used, with slight changes, for pumps, windlass, and capstan, too—was a later development that appears to owe much to African-American work songs.