Bob Dylan's first satellite radio show aired on Wednesday

Dylan's show Theme Time Radio Hour sees him play songs connected to a different theme every week - from mothers, the police, whiskey, cars, and - in the first programme - the weather.

But Dylan is not the only music star broadcasting on satellite radio.

Singer and guitarist Tom Petty also has a show, while rapper Eminem hosts his own slot on XM's rival satellite broadcaster Sirius.

Greg Steele, senior director of programming at Sirius, tells BBC World Service's The Beat programme that signing up high-profile hosts has been "one of the real drawing powers of satellite radio".

"There's a significantly large number of people who have, I think, helped move the needle and shown the kinds of programming and content that satellite programming provides," he says.

Eminem is a presenter on Dylan's rival radio channel Sirius

XM and Sirius share the North American satellite broadcasting market while WorldSpace operates in Europe and Asia.

The broadcasters charge fans to subscribe and XM claims more than six million subscribers, while Sirius's figures stand at four million.

They offer more than 100 channels each, split between music and speech.

Mr Steele said the difference between satellite and FM stations was "really about content".

"We have 67 music channels of commercial-free music," he says.

"We've got a multitude of unique and creative channels which you can't find anywhere else."

Another reason for satellite radio's rise is that it can broadcast to music lovers whose tastes are not usually catered for on commercially-available terrestrial radio.

Satellite radio creates niches and opportunities for the kinds of music fans that have not been satisfied over the last few years Greg Steele Sirius

"There is a certain amount of homogenisation of the product in terrestrial radio," Mr Steele says.

"Satellite radio creates niches and opportunities for the kinds of music fans that have not been satisfied over the last few years."

But there have been criticisms that satellite radio is in fact reducing the variety of radio stations by concentrating listeners on just two nationwide broadcasters.

In particular, XM and Sirius compete for contracts with car manufacturers to have their receivers installed in their vehicles.

"Shock-jock" Howard Stern turned to satellite to escape censorship

Sirius has exclusive deals with Ford, BMW and Daimler-Chrysler, for example, while XM-only receivers are built into cars made by General Motors and Honda.

Satellite broadcasters are not regulated by the US media watchdog, the Federal Communications Commission (FCC) - a fact that has attracted controversial hosts such as "shock jock" Howard Stern.

One of the key reasons for satellite radio's growth has been its freedom from political and commercial constraints, Mr Steele says.

"We can play the sorts of things that listeners want to hear - whether it's a racy song or an unedited piece of music," he says.

"Certain channels we do keep a little bit more for the family, but there are others where we just let it fly.