I replaced Spotify with a homemade FM radio station

$140 for a solution that works with existing receivers compares pretty nicely with, say, Bluetooth speakers (starting at about $50 and running well north, per set).

I've a number of FM-capable tuners lying around, and could pick up more quite cheaply. The transmitter's the key kit.

FM broadcasts do a high pass at 50 Hz and stop at 15 kHz. The best SNR is only ~50 dB which is already achieved by plain old SBC. There is no need for higher fidelity audio codecs like AAC/aptX/aptX HD/LDAC besides the fact that most smartphones don't support aptX or aptX HD.

You'll want to be "kind" to the extant spectrum and do a responsible frequency sweep to select the "quietest band" prior to broadcasting. And you'll only want to broadcast during the event itself.

The FCC has better things to do than to try and track down an ephemeral milliwatt infringer.

The Part15 regulations for AM and FM are more subtle then what you present here. On FM it is based on field strength readings, the exact values of which escape me, but yielding roughly the range you describe.

For AM the rules are more interesting. You can have up to a 3m antenna length and 100mW of DC power input to the final stage of amplification. The optimal setup is a class E amplifier with ~95-99% efficiency into a properly grounded 3m base loaded vertical antenna. The antenna will be grossly undersized but you try to compensate with a huge loading coil. In ideal conditions this setup can get you about 0.5km range.

LPFM is a much more significant undertaking and it is not trivial to get an LPFM license. I know because I have one :)

The bandwidth for AM transmissions in North America is only 20 kHz and radio emissions has to STRICTLY fall within that bandwidth. Technically, it allows an audio BW of 10 kHz, but in practice it is close to 4 kHz which is telephone quality.

Not suitable for Music.

The Ed Sullivan Show American Bandstand Soul Train

Top of the Pops BBC

One of the guys from Nirvana wrote a good essay on how Billboard destroyed music in the 1980s by consolidating the number of radio markets feeding the chart and allowing ways to trick the top seller lists. Before the MTV modern billboard era there used to be local artists on local radio and eventually one might break out onto other markets and eventually break nationally. Then artists became famous simply due to being good looking, having a catchy producer driven sound and a corporate machine getting them into everyone's ears. Things were a little different from the late 60s to the early 90 and some artists broke out organically.

Here is an example of a station that was independent an influenced early MTV programming during their first couple of years. WLIR documentary, 'New Wave: Dare to Be Different,' chronicles the rise and fall of one of the coolest '80s radio stations.

A funny example of a non-corporate act was the group KLF who hacked the Top of The Pops formula and got onto TV with absurdity. A documentary about them is called "Who Killed the KLF".

Are we being 'nudged' to like certain genres or musicians because they are being promoted? Of course, this could happen with a DJ or traditional FM station too, but with centralized AI, you impart that 'nudging' on literally millions of people.

Indeed - radioparadise.com is a quite nice Internet Radio

It's much better than what I've experienced with spotify and similar and it's way less effort. I had built a pretty big launchcast preference profile, but it took years of active listening, and in my genre remixes are preferred over original recordings but radio on demand doesn't have them ... you need currated collections, and I'd rather not be the curator.

I do worry about the longevity of the subscription service though... at least some of the channels are very repetitive, it feels like someone set up a currated rotation a while ago that just continues to repeat. They did the sec crowdfunding several years ago and there was a lot of related party transactions that looked too squishy for me, and after the offering expired they did the required years of reporting and its a blackbox again.

Clear Channel didn't really expand in a major way until about the mid-1990s, owning 43 radio stations in 1995, following legislation relaxing station ownership limits (for both radio and television) in 1992.

For those recalling 1980s or earlier radio in the US, the situation was rather more diverse, particularly in ownership, though fairly narrow segment programming was becoming the norm as professional "programmers" entered the field.

More largely, the history of popular music has run through multiple phases of diversification and consolidation as new performance, recording, and distribution technologies emerged. I covered this referencing the work of Charles Perrow some years ago: <https://news.ycombinator.com/item?id=24930562>.