Sure  As a term the list may be more common now than the radio format  I was just tired of putting top  in articles and having it come up red  I do think the radio format was first though  Having  songs in rotation is just about the right number  I remember some Top  stations and they just didnt make it  Too repetitive even for pop radio   On the other hand I noticed the same thing about the links that you did and stopped making them  I cant quite imagine the content of the US Top  and UK Top  articles  I suppose they could be lists of annual top  lists   The radio format is important for noting all the wack songs that have made it  The Mormon Tabernacle Choir is not what you usually think of as a Top  group but because of the radio rules there it was mixing it up with the pop bands