Improvisation and stock verses were the tools of the trade of shantymen. Similar to the blues, shanties often exhibited a string of such verses without much explicit or continuous theme. While on one hand this may simply reflect the aesthetic of the music-culture from which the form originated, this, too, was a feature suited to practical restrictions. Work tasks might be of any length and often unpredictable. Songs with a fixed set of verses, or ballads, which tell a story, were not so well suited to tasks that could end abruptly at any time or that might require extending.