You don't need to pull up a stock chart to conclude that Sirius XM Radio (SIRI) had a good week. The market rallied after the fiscal cliff was temporarily sidestepped, and Liberty Media (STRZA) received regulatory clearance to take control of the satellite-radio provider. That was a potent one-two punch to drive the to a four-year high on Friday, soaring 7.3% on the week. The Dow's 3.8% ascent and Nasdaq's 4.8% pop were nice, but those heady gains pale in comparison.

There was also a lot happening in the realm of streaming radio, where Sirius XM promises to be a big player in 2013. Pandora's (P) stock hit a three-month high, even though a Wall Street analyst pointed to the rollout of an Apple (AAPL 1.27%) streaming service later this year. Meanwhile, Global darling Spotify, in an interesting development, stopped selling digital downloads.

Let's delve a bit deeper on all things Sirius XM.

Give me Liberty
It was a forgone conclusion that the FCC would clear Liberty Media's push to gain majority control of Sirius XM. This has been Liberty Media's vocal intention since it began growing its effective stake in the satellite-radio giant from 40% in March of last year to 49.8% today.

Liberty Media was waiting on the FCC to push its stake to at least 50.1%, and it's quite possible that this happened on Friday. The stock spiked to $3.15 early on Friday with heavy volume. We'll know more soon. Liberty Media indicated that it will boost its stake to more than 50% within 60 days of Thursday's decision, but why wait?

Sirius XM is at its highest level in 58 months. The longer Liberty waits, the more this win-win scenario becomes a losing proposition, since Liberty will have to pay more to complete its position if Sirius continues to climb. On the other hand, of course, if Sirius XM begins to slip, the value of the likely spinoff will diminish.

Cupertino looks to take a bite
BTIG analyst Richard Greenfield is speculating that Apple's oft-rumored premium streaming service will launch later this year. This matters to Sirius XM, which expects to roll out its own personalized streaming radio service shortly.

Apple will make a dent here. It's not just that Apple is the country's dealing music retailer. Greenfield expects Apple's "Pandora killer" to be incorporated in the industry-standard iTunes Store, raising the bar by making it easy for users to buy concert tickets and make music purchases.

Premium streaming and e-commerce make sense, but they're not a slam dunk. Spotify, for now, has nixed the MP3 store that it used to make available in Europe. That may not be a permanent decision, but this week's update does away with in-app purchases. This is a surprising retreat. Even if Spotify wasn't selling a lot of music, as eyeing digital purchases is one of the reasons to get excited about Sirius XM's focus on pumping up its average revenue per user through its emphasis on making its streaming platform stickier.

Pandora rises above
The threat of Apple has been weighing heavy on Pandora, but shares of the music-discovery pioneer still broke into the double digits for the first time since early October with this move.

Pandora isn't going to take the Apple challenge lying down. The dot-com speedster revealed that its CEO will be presented at Citi's summit during next week's media-magnetic Consumer Electronics Show. He will present on Monday after the market close.

He won't be alone. Sirius CFO David Frear will present at the same conference on Wednesday morning.

So, yes, it was a great week to be long Sirius XM. The regulatory nod for Liberty Media is big. However, the week ahead promises to be just as interesting, as investors check filings to see whether Liberty Media did boost its stake.

Sirius XM is never boring.