Spotify, the European online streaming music service, has finally launched in the United States after months of anticipation by fans and critics alike. As Hayley Tsulayama reported:

Spotify, the streaming music service popular in Europe, launched in the U.S. today, after months of speculation. The service has signed deals with the four major music labels in the country, reported All Things Digital, finally giving the green light to launch.

Spotify is a streaming music service that lets users create playlists and share them with their friends. For now, the free service is by invitation only, but it is expected to open up in the coming weeks. Paid plans are available immediately.

The U.S. launch has three plans, much like the plans available in Europe. The free, ad-supported service gives users access to a number of tracks on Spotify through the Web, lets users organize and jam to their own music and gives access to Spotify Social. According to Spotify spokeswoman Alison Bonny, the free service that launched today has no time limits as part of an introductory offer, but Spotify will eventually cap users to 20 hours per month, the same model it has in Europe

Spotify Social is the realization of the site’s rumored Facebook integration, and it lets you post playlists to which your friends can subscribe.

You can also import your Facebook friends into your Spotify profile and share tracks by using the service’s Inbox. The inbox lets you know who has shared a particular song with you and when they sent it.

For $4.99 per month, users also get to ditch ads and get access to the Spotify radio mode. For $9.99 per month, you get mobile access to your playlists, access to offline modes for your desktop and mobile device and access to exclusive content.

While some critics question the the impact Spotify might have on the U.S. online music market, some music experts say the service is worth the hype. As Elizabeth Flock explained:

While music lovers wait for the free service, BlogPost got the lowdown from Merlin, a U.K.-based nonprofit music organization that represents more than 10 percent of all artists’ tracks streamed on Spotify.

In a Q&A, Merlin CEO Charles Caldas talks about whether Spotify is worthy of the hype, why independent music does so well online, and how to get that elusive invitation. Merlin represents independent artists that include Arcade Fire, Adele, The National, Spoon, The Strokes, Social Distortion, and Vampire Weekend.

Is Spotify really worthy of all the hype?

I think so. Spotify is the world’s largest music subscription site. It has a great Web site, they understand how to be interactive — such as the way people can easily share playlists on Spotify, and they understand the digital economy.

Many businesses like Spotify have come and gone because they failed to understand that you can’t just have the major labels. Listeners have tastes that are much deeper and broader.

What do you mean by deeper and broader?

People want to listen to independent music, too. Independents this year topped the charts. Look at Arcade Fire, Spoon, the National. And there’s a 50 percent uptick on the number of people who are interested in independent music when they access the music digitally.

The launch of Spotify has been buoyed by promotion from several celebrities and musicians, who took to the social networks to rave about the music service. As TechCrunch reported:

Music service Spotify has finally crossed the pond; arriving in the U.S. this morning. The service offered a limited number of free invites, but you anyone can start using the service if they shell out $4.99 or $9.99 per month. Twitter is actually exploding with mentions of the service. And considering all the hype behind the European startup, it’s not surprising that Spotify has already gotten a few endorsements from celebrities and musicians.

Britney Spears Tweeted about her excitement for Spotify to arrive yesterday afternoon, and followed up with a message this morning with invites for the service.

Nine Inch Nails’ Trent Reznor (who also wrote the score for The Social Network), Tweeted “Finally! Spotify is coming to the US. I’ve been using this for a while and it’s great.” Like Spears, Reznor generously followed up with free invites for followers.

Unsurprisingly, actor and tech investor Ashton Kutcher heaped praise on Spotify earlier today, Tweeting “What a relief, now that it’s legal in the US, I can finally come out of the closet about my #Spotify addiction.”

As my colleague Alexia Tsotsis wrote a few weeks ago, for many startups, “The Celebrity Moment” is a major milestone the company’s service. That could be the case for Spotify.

More from The Washington Post

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Can radio withstand the Spotify assault? A feature-by-feature look

Don’t have a free Spotify invite? Use your Klout perks