Twitter will launch a music service over the weekend, and maybe as early as Friday, say Mike Isaac and Peter Kafka at All Things D. How do they know? The microblogging site isn't exactly keeping it a secret. On Thursday, Twitter confirmed that it had purchased (and hit pause on) music-recommendation service We Are Hunted. Then it went live with a dummy page for Twitter #music. And finally, Ryan Seacrest told us:

It makes sense that Seacrest would be one of the first people to beta-test Twitter Music, says Jeremy Cheong at Hardware Zone. Along with his American Idol duties, he's also the host of the radio program American Top 40. And if you think that perhaps Seacrest is trolling us all, Kevin Thau, Twitter's VP of business and corporate development, gave a quasi-official stamp of approval to the rumor by re-tweeting Seacrest's teasers.

What will a Twitter music service be like? Twitter and We Are Hunted are being tight-lipped about this. But we know it will be a stand-alone app, not part of your Twitter stream. And social media is, of course, a big part of the deal. "Twitter Music is said to suggest artists and songs to listen to based on a variety of signals, and be personalized based on which accounts a user follows on Twitter," says Steven Musil at CNET.

It being Twitter, music lovers will also reportedly be able to see what songs are trending among all users. That's a no-brainer, says Mashable's Chris Taylor. "We Are Hunted focused on the top trending music on social media," and it would be silly if Twitter didn't do the same. According to an earlier report from CNET, the new app will be divided into four sections — "Suggested," "#NowPlaying" (a list of songs tagged with that hashtag by people you follow), "Popular," and "Emerging" — and you won't have to have a Twitter account to sign up.

"Users will be able to listen to clips of music from inside the app, using third-party services like iTunes, Soundcloud," and Rdio, say Isaac and Kafka at All Things D. "They will also be able to watch music videos provided by Vevo, the music video service owned by Universal Music and Sony." Here's We Are Hunted's Stephen Phillips testing out a possible template in February:

We still don't know quite a few things about Twitter Music, though. CNET says the first iteration will be an iOS app, so "Will this be one more app that Android users have to wait more months to experience?" asks Mashable's Taylor. Does the website suggest there will be a web browser version, too? Will people be able to steam entire songs on demand, or just clips? And does the dependence on existing services like Rdio and Soundcloud mean that Twitter doesn't have to ink deals with the record labels?

Then there's this question: Why?

Well, why not? says Kit Eaton at Fast Company. "Music discovery and Twitter would seem to be a perfect marriage," and the timing is great: Apple reportedly just got Universal Music, the world's biggest record label, to sign on to its widely expected iRadio service, and Facebook is rumored to be ramping up its music offerings, too.

The other reason, says Casey Newton at CNET, is growth. Twitter understands "the key role music has played in drawing new users to the service — particularly younger, mainstream users."

Pop stars have some of Twitter's most popular accounts, with followings in the tens of millions. The TwitterMusic account has 2.3 million followers — not a bad perch from which to launch an eponymous app.... The question for Twitter will be whether a groundswell of users find the app useful enough to displace the existing options for music discovery, which are numerous and popular.... Twitter Music looks fun to browse, but it may find it hard to compete against more full-featured music apps, which among other things allow for offline storage of songs.

Still, Twitter Music represents an intriguing effort to take the many successful artists broadcasting on the platform daily and use them to form new relationships with their fans. In time, it's easy to imagine Twitter integrating ticket purchases or other e-commerce into the app. For now, though, music fans can only watch and wait as Twitter puts the finishing touches on one of its most interesting experiments to date. [CNET]