Sŵn y Glaw is the name of a house near where I work. Bit depressing, don’t you all think? 
Another one I heard but cannot find is California Dreamin’ redcorded in Cymraeg by Y Nhw "Cwympo Mae Y Dial. I’ve got a low tech recording off Radio Cymru just for myself as I can’t find it anywhere!
EDIT: Just found it on Youtube!!! https://www.youtube.com/watch?v=qmKGjolnHuI
Moving the question in this topic in case someone else would like to join the discussion.
besides @siaronjames and @Hendrik.
I’ve checked songs previews, and my favourite is certainly Alcatraz (playing Bibopalwla’R Delyn Aur).
Does anybody know them?
Then, among those I’ve never heard, I would be curious to hear something else by Estella (onthe comp, playing Dim Ond Cysgodion) and Maharishi.
But with names like these, there’s no way I can reach any results in Welsh from Google, too much other stuff with the same names! 
Also…curious to hear other opinions here. I had kinda missed Meic Stevens singing in English before seeing the documentary.
I know that singing the same song in different languages change a bit because of the sound of the language itself, the metrics and so on.
But is it just my impression or he also changes a lot his singing style in most of his songs in English?!
Maybe it’s also a coincidence cause they accidentally are from a specific period and the music in general have a sound that’s closer to my taste…but anyway, still curious to hear more opinions!
p.s. his Welsh accent is one of my favourites, anyway!
Estella made 2 EP CDs and 1 album - this is the album -
https://sainwales.com/index.php?/store/sain/sain-scd-2432
This is the 2nd EP - https://www.ebay.co.uk/itm/Estella-Tan-Welsh-Language-Cd-Estella-Records-2002/264531038346?hash=item3d9747508a:g:IgoAAOSwlj9dwb1y
Oh, and the lead singer of Alcatraz was Cate Timothy aka Cate Le Bon - she does a lot of solo stuff now.
For some reason I had seen the links of the Estella records, but missed the last part of your post.
It’s interesting I picked Alcatraz, even though I totally hadn’t recognized the voice: Cate Le Bon is one of my favourite new Welsh artists!
Personally, I’m glad you picked Estella! Great line-up back then!
Oh!!! 
The other day I had checked and bookmarked the link to Sain page but hadn’t read through the bio…until now!!! 
You’re so fast at finding things that Probably not even Pat herself has seen it!