Puirt á beul is a style of singing from a place called Gaelic Scotland. It is really cool because it's like having a conversation through singing.
Basically, when people sing puirt á beul, they use their voices to create music without any musical instruments. They make different sounds with their voices to mimic different instruments like drums and flutes.
The words they sing are usually in Gaelic, which is a special language from Scotland. It might be hard to understand if you don't speak Gaelic, but it's okay because the singing is so beautiful that you can still enjoy it even if you don't understand the words.
So imagine talking with your friends, but instead of speaking, you use your voice to make music! That's what singing puirt á beul is like.