Awhile back I was commenting that it seemed like I kept on hearing the same 10-15 songs playing from every radio station I encountered. And that it seemed to me that FO3 hat a _lot_ more songs in the base game. LateWhiteRabbit was kind enough to Reply with:
"There seems to be a problem with the radios not playing the full list of songs at the moment. They are set to randomize the songs, but something is not right with the scripts, so they end up repeating the same handful again and again. In actuality there are 48 radio songs in New Vegas, as opposed to only 20 in FO3, we just aren't hearing them all at the moment."
After well over 200 hours of gameplay, I _still_ had yet to hear more than 20 songs, so I looked around to see what I was missing. Given clues at YouTube, I discovered that apparently I was still not getting everything that is available, even after a recent hefty patch of fixits. So I dug further and discovered this info: FNV = 27 songs http://fallout.wikia.com/wiki/Category:Fallout:_New_Vegas_songs. Of those 27, I had yet to hear 9 of them.
In contrast, FO3 = 37 songs http://fallout.wikia.com/wiki/Category:Fallout_3_songs.
I'm definitely looking forward to somebody creating a mod or patch that expands the radio music to something between 50 and 100. [However, because of Mr New Vegas's frequent intros, it's unlikely that they will call Wayne Newton back to do additional intros. Which means that the premier Mojave station isn't likely to expand its playlist any time soon.]