That's annoying...a little about the radio and technology.

...the radio station I usually listen to was broadcast over by some new hip-hop station. So now most of what is on it is 50Cent saying he likes women like a fat kid likes cake, take him to the candy shop, he wishes he had mint now, etc. It's all quite the masterful use of metaphors. The depth is amazing: "Me like candy." "Me no like not having candy."

But anyway, beginning to criticize one genre or another is not the point of this post. The point is that radio is still running on 1950s technology thanks to the government. The bandwidth being used could actually trasmit about eight more stations, or even more, if the bits were used more efficiently. With respect to radio, the government is like a protectionist system for the polluters or the gas guzzlers of the Information Age. I.e., those who make terribly inefficient use of broadcast bandwidth, the natural resource being used. I'll try to explain things for the non-technical, if you are still bothering to read this. This one is probably for geeks.

bandwidth is:
1 : a range within a band of wavelengths, frequencies, or energies; especially : a range of radio frequencies which is occupied by a modulated carrier wave, which is assigned to a service, or over which a device can operate

As far as radio, the bandwidth involved is a portion of the electromagnetic spectrum being used and misused. Misused because the situation with respect to broadcasting on the spectrum is analogous to people being in a room of limited space all trying to shout over each other instead of modulating their tone and voice so that each one can be heard and have a conversation. Thus, now there is a new hip-hop station here instead of the other station. The government helps to sponsor the situation because it auctions off the spectrum in blocks based on 1950s technology, there is no incentive to use it more efficiently with new technologies. One technology that most people have at least heard of is MP3. That is a rather old audio technology originally developed by the Fraunhoffer institute. It's a codec, a coding/decoding algorithm. It works in pretty simple ways by removing portions of the audio that are in inaudible regions of its spectrum, at least to the human ear. That alone saves a lot of space. Then it also uses psycho-acoustic masking tricks like useing less bits for a high portion of the audio while there is a booming bass part. If all goes well you will never hear the difference. But if there is not enough bitrate to use then you may hear a warble or "flanging" in the high portions.

If there was any incentive for an efficient use of bandwidth in the case of radio then such algorithms and codecs could be used.

"....using digital signal processors, a radio can be made to disassemble a stream of data fed into it from a source. It can be made to do this right down to the sub-byte level - bundle it into tiny packets of data, and transmit those packets in short bursts in random ways over a wide range of frequencies. . . .
This can be done at low levels of power, while a corresponding radio at the other end, using the same proprietary algorithms used by the first radio, can capture and
analyze those packets, re-assemble them perfectly, and feed them into a receiving system or network.

Secondly, error-correcting techniques possible for digital signaling can even deal robustly with the interference that does occur. If a great deal of interference occurs, the usual effect is the slowing down (from retrying to get the signal through perfectly) of the rate of data exchange, not its complete failure. . . . .

In other words, spread spectrum, using frequency hopping techniques can co-exist with other radios using the same frequencies or bands. In fact there can be 'spectrum sharing' to such a degree that it is no longer necessary for the FCC to award licenses to just one transmitting entity operating in an area. There still have
to be rules, of course, but very different rules, for this new era of digital radio."
(David R. Hughes, The Case for Shared
Wireless Public Spectrum)

Inefficiency and waste becomes important politically because Leftists tend to favor something called the "fairness doctrine." Because the resource is supposedly scarce (And thanks to the governments way of auctioning it off, it probably always will be "scarce.") we have to be "fair" in its usage. In other words, what you talk about is going to be policed.

Instead of efficiency, here is what we have. An analogy using the natural resource of audible airtime:
"You are at a crowded party. As is typical of parties, many people are carrying on conversations at once, and the air is full of noise. In fact, you are having trouble hearing what other people are saying due to the din. Suddenly, the door opens,
and several federal agents appear, badges in hand. "Your attention please," their leader says sternly. "Because so many people are talking too loud, causing others to have trouble hearing their own conversations, the newly-established Federal Speech Commission will now exercise its plenary authority to regulate conversations. Since some of you are having trouble hearing each other, we decree that in order for anyone to have a conversation for the rest of the night, you must first get our permission--and we will base our permission on whether you can convince us that your planned conversational topic is indeed worthy of discussion (after all, sound waves are scarce, and we wouldn't want anyone wasting perfectly good sound waves on chit-chat). Furthermore, we will not allow any improper language, and we would appreciate your efforts to talk about serious subjects such as philosophy, politics or foreign affairs. Thank you for your attention, and you can begin lining up to get permission to talk."

As time went on, everyone got accustomed to the Federal Speech Commission, and its officious regulation of any and all party conversations. Before long, however, a few people had a bright idea. Instead of having the FSC representatives decide on who got to speak and when, why not allow the people themselves to decide as long as they bought the right to do so? That is, let the FSC sell off the right to speak at parties, and whoever wanted most to speak could simply bid the highest. It would make money for the government, and would encourage economic efficiency. It also seemed like a step towards personal freedom.

Of course, since sound waves were scarce, and since the FSC still had authority to regulate and allocate the right to talk, it would be necessary to have restrictions on the subjects that could be discussed, or the language that could be used, or on the number of talkers allowed at any one time. And despite the FSC's admirable purpose, something seemed faintly amiss about the government selling the right to speak, whether at parties or elsewhere. No one ever seemed to consider how it was that the government could claim the right to sell speakers' licenses in the first place. Nevertheless, the auction idea took off, and the FSC busied itself with raising exorbitant amounts of money thereby."
(Leland Stanford Junior University
Stanford Technology Law Review
2002 Stan. Tech. L. Rev. 2
Replacing Spectrum Auctions with a Spectrum Commons
Stuart Buck)

To the non-techies, I apologize...anyhow, those are some of the reasons that one radio station is broadcasting over another one.