In Gaelic, we don't say that someone "wrote" a song, we say that they "made" it. Gaelic certainly had a great history of writing but much of Gaelic culture was oral - meaning that people didn't tend to pass on information by writing it down. In fact, Gaels developed their memories so well that some could remember hundreds of songs or be able to sing a song from beginning to end after hearing it just once.
Like many cultures, the Gaels had songs for all sorts of activities: milking, lullabies, dancing, spinning, weaving, rowing, churning, and milling the cloth. There were also songs made in praise of people, recalling special events or even poking fun at certain people.
Known sometimes in English as "Mouth Music", Puirt-a-Beul were sung to well-known fiddle or bagpipe tunes - mostly strathspeys and reels. They would often be sung if no instruments were present, so that people could stepdance to them. The words of the songs are often silly, but suit the rhythm and beat of the original tunes. Puirt-a-beul was a way to teach tunes before they were written down.
Listen to the following tunes being said and then sung, so you can learn them!
Link
Strathspey
Calum Crùbach as a' ghleann
Cum thall na caoraich uile
Calum Crùbach as a' ghleann
Cum thall na caoraich
Cum thall na toir anall
Cum thall na caoraich agam
Cum thall na toir anall
Cum thall na caoraich
Crooked Calum from the glen
Keep all the sheep over here
Crooked Calum from the glen
Keep the sheep over here
Keep them over here
Don't let them go over there
Keep them over here
Keep the sheep over here
Reel
'S iomadh rud nach saoil sibh
'S a' mhuileann dubh, 's a' mhuileann dubh
'S iomadh rud nach saoil sibh
'S a' mhuileann dubh as t-Samhradh
Tha 'm muileann dubh air thuraman
Tha 'm muileann dubh air thuraman
Tha 'm muileann dubh air thuraman
'S e togairt 'dol a dhannsa.
There are many things that you'd not imagine
In the black mill, in the black mill
There are many things that you'd not believe
In the black mill this Summer
The black mill is turning
The black mill is turning
The black mill is turning
And wanting to make us dance.
Now watch Carmen MacArthur of Gillisdale dancing to these puirt-a-beul.
Link.
Learn the 'Hop Step', the most basic step used to dance to a reel.
Link