With a good internet connection, which is like disposable resource in the west (I don't know of anyone who had limited bandwidth plans) people catch up with music for free, without downloads and stuff.
Get an Android phone, install apps for internet radio.. like Pandora, TuneIn radio, spotify etc.,
On some services like Pandora (my fav) you can create an account and filter genre's of music and save. you can click on a genre, and you hear streaming-audio, non-stop random music (of your genre) that keeps playing forever. Assuming, you go on a long drive, have charged your phone, and have an unlimited internet data plan, you are all set. Don't buy that iPhone and pay for music on iTunes.. unless you want to limit yourself to a particular sub-set of music.
In my opinion: If you get to limited music through purchases, you should actually not be bothered about marketing phrases like "1 billion songs to choose from".. because you are not going to be able to buy all of that.
Yes, internet free radio won't play new music very often since they pay a broadcasting fee to the creator. but they do play new music sometimes.
And ah! there will be ads in between music playlists.. and also onscreen popup ads, to make up for the money the radio loses when you hear it for free. But I think its very tolerable ad-time compared to FM radio.
And here's a good graphic on comparison between Spotify and Pandora. The comparison though seems to be outdated on the cost part.. because my Spotify is free only for 3 days... unlike what the graphic mentions.