Garbledowen

TFSmith chooses to open Chapter 3 part 1 with the lyrics to Garryowen, which he suggests to be:

Instead of port, we'll drink brown ale
And pay the reckoning on the nail

This is a rather unusual interpretation of the lyrics. Port, for those who are unfamiliar with it, is a sweet red wine which has been fortified with a grape spirit called aguardente; this makes it stronger than standard wine (c.20% ABV rather than c.12%). It was an upper class drink, popular in the London clubs, with Pitt the Younger and Sheridan boasting of their ability to drink three bottles of port in a single sitting. Brown ale, meanwhile, is a moderately strong beer of around 6% ABV, primarily drunk by the lower classes.

The actual first line should be Instead of water, we'll drink ale or Instead of spa, we'll drink brown ale
(spa, of course, being water derived from mineral springs). As for the second line, it should be And pay no reckoning on the nail. 'The reckoning' is, of course, the bill, and to pay 'on the nail' means to pay immediately.

In other words, TFSmith's version of Garryowen has the singers boasting about drinking cheap, relatively weak alcohol and paying up when they're asked to. This perhaps explains why For debt no man shall go to gaol: however, it certainly takes away some of the arrogant machismo that made Garryowen so popular in the first place.