http://www.youtube.com/watch?v=YNONlNLUVvU
The O'Kellys sing Abba
Published on Apr 10, 2012 
Fergus, Grainne, Catherine and Deirdre O'Kelly sing a medley of Abba songs arranged by Deirdre especially for Lisa's [50th] birthday party on 10th March 2012

in other words

if you include something like 'Abba'

in the word-framework on your otherwise obscure YouTube entry

you will attract more

'hits'

[and make it easier to find on search engines]

than if you ....