He sounds okay, there were a coiuple of dodgy spots but the lyrics may just be different from the subtitles.

For Donegal Irish, I'd recommend Mairéad Ní Mhaonaigh, Máire Ní Bhraonáin (Moya Brennan), Mícheál Ó Domhnaill, Tríona Ní Dhomhnaill and Maighread Ní Dhomhnaill. The last three siblings were in Skara Brae and two of them were in the Bothy Band.

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Múinteoir Gaeilge - Irish Teacher
My "specialty" is Connemara Irish, particularly Cois Fhairrge dialect, but I can also speak Ulster and Munster Irish with native-level pronunciation.
Is fearr Gaeilge ḃriste ná Béarla cliste, cinnte, aċ i ḃfad níos fearr aríst í Gaeilge ḃinn ḃeo na nGaeltaċtaí.
Gaeilge Chonnacht (GC), go háraid Gaeilge Chois Fhairrge (GCF), Gaeilic Uladh (GU), Gaelainn na Mumhan (GM), agus Gaeilge an Chaighdeáin Oifigiúil (CO).

From what I’ve read, although born outside of Gaeltacht (Belfast), he was friends with a Donegal native family and in his youth he’s spent a lot of time in Rann na Feirste in Donegal Gaeltacht. In the 80s he also was a president of the Conradh na Gaeilge.

For Munster (Kerry) Irish, Séamus Ó Beaglaoich (Séamus Begley), Dingle native, has IMO very clear pronunciation, currently there are some of his songs on Youtube: An tSeanbhean Bhocht, Bruach na Carraige Báine (with Mary Black), Ar Éirinn Ní Neosfainn Cé hÍ, An Ciarraíoch Mallaithe, Aililú, na Gamhna (with Louise Morrissey). Spotify also has a few (eg. Amhrán na Leabhar).