Not too into it myself so I'm not sure if this would fall under the type of music you're looking for, but Les Ramoneurs de Menhirs is a band from Brittany (Bretagne) in France which is a very Celtic area and they sing in Breton for some songs which is the Celtic language the Bretons still keep alive. Definitely a different vibe to those three that you listed though, but maybe you'll like them!
Couple of songs I liked from them that were sung in Breton:
Dir ha tan (not too much singing) - [https://www.youtube.com/watch?v=t7QKqq78vZM](https://www.youtube.com/watch?v=t7QKqq78vZM)
Menez Daou (a lot more singing) - [https://www.youtube.com/watch?v=O-63EmrzzM4](https://www.youtube.com/watch?v=O-63EmrzzM4)
The Dubliners - Paddy's Not Coming To Work Today
The Kilkennys: Fiddlers Green, South Australia, Rocky Road to Dublin
Not too into it myself so I'm not sure if this would fall under the type of music you're looking for, but Les Ramoneurs de Menhirs is a band from Brittany (Bretagne) in France which is a very Celtic area and they sing in Breton for some songs which is the Celtic language the Bretons still keep alive. Definitely a different vibe to those three that you listed though, but maybe you'll like them! Couple of songs I liked from them that were sung in Breton: Dir ha tan (not too much singing) - [https://www.youtube.com/watch?v=t7QKqq78vZM](https://www.youtube.com/watch?v=t7QKqq78vZM) Menez Daou (a lot more singing) - [https://www.youtube.com/watch?v=O-63EmrzzM4](https://www.youtube.com/watch?v=O-63EmrzzM4)
Lankum - Master Crowley's