To me cydnabod means recognise in the sense of, say, recognising authority or responsibility. I would use adnabod or nabod for recognising (subtly different from knowing) a song. Your mileage may vary, though.
Diolch…i had written adnabod but got cold feet reading discussions online doh damia! 
Acknowledge is the word I was looking for. 
Al Lewis Trywydd Iawn
That’s Owen Powell’s son on bass, BTW.
Melys/ Sweet
I’ve been trying to find this for ages. Thanks to @Oddsandgirl Sandy’s husband Kelvin for finding it for me. Brings back memories of Welsh camp at Bala in the late 70’s where we even had to translate a pop song and perform it …“Wrth aflonydd Babylon” lol…
Los Blancos - Ti Di Newid
I found this video in the YouTube topic “Los Blancos” but beware their songs have been merged with songs from the American band of the same name, the same if you search google for their list of songs!
The best place to find their stuff is on their record label’s soundcloud.
They’re playing at the PizzaTipi in Cardigan tonight, if anyone’s interested.
alaw mor ysgafn â’r gwlith / gentle sound
One of the founders of the Velvet Underground John Cale sings an interesting rendition/interpretation ( Cymraeg: dehongliad) of the classic Ar lan y môr
cerddoriaeth optimistaidd!? 
Elin Fflur air Band -Teimlo
fideo diddorol go iawn
fy hoff gân