For more than 30 years the Shortwave radio spectrum has been used by the world's intelligence agencies to transmit secret messages. These messages are transmitted by hundreds of "Numbers Stations."

Shortwave Numbers Stations are a perfect method of anonymous, one way communication. Spies located anywhere in the world can be communicated to by their masters via small, locally available, and unmodified Shortwave receivers. The encryption system used by Numbers Stations, known as a "one time pad" is unbreakable. Combine this with the fact that it is almost impossible to track down the message recipients once they are inserted into the enemy country, it becomes clear just how powerful the Numbers Station system is.

These stations use very rigid schedules, and transmit in many different languages, employing male and female voices repeating strings of numbers or phonetic letters day and night, all year round.

The voices are of varying pitches and intonation; there is even a German station (The Swedish Rhapsody) that transmits a female child's voice.

One might think that these espionage activities should have wound down considerably since the official "end of the cold war," but nothing could be further from the truth. Numbers Stations (and by inference, spies) are as busy as ever, with many new and bizarre stations appearing since the fall of the Berlin wall.

Why is it that in over 30 years, the phenomenon of Numbers Stations has gone almost totally unreported? What are the agencies behind the Numbers Stations, and why are the eastern European stations still on the air? Why does the Czech republic operate a Numbers Station 24 hours a day? How is it that Numbers Stations are allowed to interfere with essential radio services like air traffic control and shipping without having to answer to anybody? Why does the "Swedish Rhapsody" Numbers Station use a small girls voice?

These are just some of the questions that remain unanswered.

The collection was released by England's Irdial-Discs record label in 1997 as a Quadruple CD set with an 80 page booklet and a postcard.

The Conet Project has since become somewhat of a cult sensation and counts many musicians and filmmakers among its fans, including Wilco frontman Jeff Tweedy, Faith No More/Fantomas/Mr. Bungle vocalist Mike Patton, and director Cameron Crowe. Samples from the collection have been used in numerous films and albums, including Crowe's film Vanilla Sky and Wilco's million selling Yankee Hotel Foxtrot album, the latter of which was an issue of legal dispute; Jeff Tweedy did not seek permission to use the unattributed Conet sample and Irdial sued for copyright infringement. The incident sparked a debate about who exactly owns copyright concerning recordings of Numbers Station transmissions, but Tweedy ultimately decided to avoid taking the matter to court, agreeing to pay Irdial royalties and reimburse its legal fees.

In 1999, the Irdial label released is entire catalogue under a license that allows the sharing of their music; you can download their entire catalogue, including The Conet Project, from the Internet Archive and they encourage fans to freely distribute their works on file sharing networks. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.