Irish songs of the sea fall into several categories: shanties, ballads, songs related to Irish folklore and legends, songs about fish and fishing, rowing songs, songs in praise of boats and laments. In his book "Irish Ballads and Songs of the Sea" James Healy describes shanties as follows:

Shanties were the work songs of the seamen. One man sang the solo
part, often improvising the words as he went along, and the other men
sang the chorus: the music provided a rhythm which made it easier to
pull ropes, or turn the capstan. Each job had its own series of shanties
had its own series of shanties to suit the particular rhythm required. (Healy 1967:26).

   For this years festival the Galway Celts have chosen to sing a popular shanty called Sally Brown. It is impossible to speculate the origin of this song. Stan Hugill (an authority or shantying) proposes that it may hail from the West Indies (possibly Jamaica) sating that some shantymen sang it as "Oh Sally Brown of Kingston City". Cecil Sharp however, collected a version of it in England in the early 1900s from a Mr Robbins of London. Mr Robbin's version has no reference to Kingston City although it does read "Sally Brown was a Creole Lady". Both Hugil and Sharp identify Sally Brown as a halyard song. The halyard is the rope which was pulled in or her to hoist the upper top sail on a sailing vessel, and this song would have accort panied the strenuous pulling on the halyard.
    Stan Hugill was himself a shanty man who worked on the sea for many years. He notes that most of the men who manned the western Ocean Packet Ships were ofIrish nationality and states:

...the Irishman - real, Liverpool, and New York
- was in no minor responsible for a good
many shanties. ....man's shanties had Irish tunes
- dance folk and march - and not only were
the words and phrases of many of the shanties of Irish
origin but in same cases it was
customary for the shantyman to sing the shanties with
an imitative Irish brogue.
(Hugill 1979 [1961]:1).