This Is My Jam sounds like a great idea for a Tumblr. After all, who doesn’t want to share photos of home-made preserves?

That’s not what This Is My Jam is.

This Is My Jam, which has launched in public beta, is a music recommendation site that lets you share the one song you’re currently obsessed with. Just one.

Your profile page shows your one ‘Jam’ along with a few characters of text and, if you like, a custom background image to drive home the point. You can share your current ‘Jam’ through Facebook and Twitter and you can follow people whose musical tastes you appreciate and listen to their current Jams. That’s what This Is My Jam is.

It’s also this: fucking delightful.

This Is My Jam is part of a growing, and overdue, movement against sharing every damn thing we’re listening to, watching, thinking and doing every hour of the day. The truth is, when it comes to music recommendations, a river of everything all your friends are listening to is absolutely useless. There’s no context, no passion, no explicit recommendation.

This Is My Jam is the precise opposite. Your friend is so utterly entranced by this song that they chose it as their one Jam. The recommendation lasts a maximum of seven days, after which they have to pick a new one. The result, in theory, at least, is a stream of pure gold.

Explains founder, Matthew Ogle: “Whenever I was out with friends in real life, my usual I-need-music-recommendations routine was asking, ‘What’s your favorite song right now?’ Rather than lists of albums, or artists, a song seemed like an atomic unit I could remember and look up when I got home.”

There is, it should be noted, no small amount of irony behind Ogle’s words. He and collaborator Hannah Donovan were part of the early team at Last.fm — the “scrobbling” service that, more than most, made it easy to track and share every damn thing you ever listened to. Ogle acknowledges the irony, suggesting that online “music identity curation” actually peaked in the Myspace era.

But, yeah, he says… “especially in the face of Facebook taking scrobbling mainstream with Spotify, it really [feels] like everything [is] being reduced to ‘just listened,’ auto-generated hype charts, and bland Youtube links shared in feed after endless feed.”

Taking music identity curation back-to-basics is a multinational effort: Ogle and Donovan are Canadian, front-end dev Ralph Cowling is a Brit, and ‘back-end systems wizard’ Andreas Jansson is a Swede. The team is based in London, but the service was initially incubated inside Boston-based music startup The Echo Nest. The company is now its own entity.

Initial reaction, says Ogle, has been positive, and “interesting.”

“People take their time, tell a story, choose not just hyped stuff but old gems as well. If you follow enough people, you get an ever-evolving playlist of great music unlike anything else out there. A few people have jokingly dubbed it the ‘slow music movement,’ but it seems to work. There are a lot of features still missing but we’re on to something.”

They are. More than 125,000 Jams have been shared so far from users including Shaun of the Dead and Hot Fuzz writer-director, Edgar Wright; comedian, Peter Serafinowicz; actor-blogger, Wil Wheaton; and music festival, All Tomorrow’s Parties.

This is my jam.

[Jam image stolen from We Love Jam. Please buy their jam.]