New iPod ShuffleIf you think the digital age in music is here, you’re right.

For the first time in recorded history, digital music sales in 2011 topped physical music purchases.

According to Nielsen and Billboard, digital music purchases accounted for 50.3 percent of music sales in last year. Digital sales were up 8.4 percent from the previous year, while physical album sales fell by about 5 percent.

Who was 2011’s most-streamed artist?  Who else?  Lady Gaga took the top spot. The most streamed single of 2011 was Nicki Minaj‘s “Super Bass”, with 84.9 million audio streams and 71 million video streams.

Adele‘s album “21” was the top selling album both in the online world and in the physical realm, and her smash hit single “Rolling in the Deep” was the best-selling digital song of the year with 5.8 million downloads.

Digital album sales ended the year with a bang, with a record 3.5 million sales in the last week of 2011.

“Clearly the plastic format was not an optimal format for selling music,” says Brian Zisk, executive producer of the SF MusicTech Summit, according to CNN/Money. “It’s a much healthier ecosystem for folks to be selling digital formats instead of physical formats. That’s the future, and the way it’s going.”

Zisk also cites the credits the rise of the smartphone as a catalyst behind the surge in the digital-music age.

“The ability for folks to purchase music everywhere has really expanded the digital marketplace,” he says. “They don’t need to go to physical store — anywhere the phone is people are able to purchase music.”