Puirt-a-beul (plural of port-a-beul, Scottish Gaelic for "mouth music" or literally "mouth tune") are Gaelic songs that were originally sung as an accompaniment to dances when there weren't any instruments available. Thus, many puirt started off as tunes to which words were added later. However, it was always the tune that remained the most important while the words were usually very simple and repetitive. But don't be fooled. Puirt may seem easy but they are in fact a very demanding style of singing.
They tend to be sung quite fast and are usually put into sets of at least two or three so correct breathing is the biggest challenge. I don't think anyone has ever died of asphyxiation after performing a particularly gruelling puirt set (what a cracking story that would be!) but if you're not careful you'll end up feeling slightly faint or dizzy and definitely in a need of a dram or two. Obviously, different singers will use different breathing techniques. The one I've been taught involves dropping a word here and there (usually at the beginning of a line) and using the gap to take a breath. After all, it doesn't matter if you miss a word or two as long as you get the tune right, and live to tell the tale. Of course things are easier when you sing in a group although then perfect timing becomes absolutely crucial. Harmonies aren't terribly popular with this form of singing but they can sound really effective as long as they're not too elaborate.
Most Gaelic singers include puirt in their repertoire but these days they're very often sung with instrumental accompaniment, which seems to contradict their original purpose. Just like so many other types of Gaelic song, especially work songs such as waulking songs, they have lost their original context. But it doesn't mean that they can't be enjoyed.
Below you'll find one of my favourite puirt-a-beul (followed by a translation). The "O's" at the beginning of the first three lines are perfect candidates for being dropped. Note also that each verse is sung twice and the whole port-a-beul is also repeated, just the way you'd normally play a tune. By the way, I don't smoke. I need all of my lung capacity for puirt-a-beul.
O tha 'n tombaca daor,
O tha 'n tombaca gini,
O tha 'n tombaca daor,
B' fhearr leam gun robh e tuilleadh. (x 2)
Gini air a h-uile punnd,
Punnd air a h-uile gini,
Tha e gini air a' phunnd,
Agus punnd air a' ghini. (x 2)
(Oh the tobacco is expensive,
Oh the tobacco is a guinea,
Oh the tobacco is expensive,
I wish you could get more.
A guinea for every pound,
A pound for every guinea,
It's a guinea for a pound,
And a pound for a guinea.)