We built an app that streams your Spotify songs to the internet so anyone can listen with you in real-time, and they don’t even need Spotify. Here’s what we learned after the first week.

You’re online somewhere. I’m online somewhere. We chat, see each other’s photos and status updates. All in real time. But our headphones are not in sync, not even nearly. We may send each other Youtube links with bands to check out, but that’s the closest we get. Had we been in the same physical room, we would have listened together. But in the same virtual room, no so much.

The DJ app just sits in the background, sending your song selections to the internet. It also shows how many listeners you have right now, and how many of them like the current track

Jacob and I wanted to do something about that. We crashed a nice agency’s office (thanks guys, especially for lunch) for a few days and built a simple Mac app and a website. Here’s how it works: It runs in the background on your Mac. Whatever you play in Spotify it streams to your personal Twinjack website, twinjack.com/your-twitter-name. Whoever visits that site hears whatever you hear, exactly when you hear it. Just like being in the same room.

A few interesting things started to happen when we got the first prototype running.

1: The music sounds better with you

Listeners see who’s playing, how many are listening, and how many of them like the track

That feeling of playing a a great track from a club and finding it has lost its special touch when you play it at home. Studies show that music simply sounds better when you know someone else likes it. We’re finding that it sounds even better when we know someone else is also listening, right now, sharing the experience.

2: Music sounds better when I play it for you

The DJ’s app icon is updated immediately when a new listener joins. The next version will have optional Notification Center push messages

This will not be a surprise for anyone who has had friends over for drinks and launched into a marathon tour of your favorite tracks. The joy reaches new heights when they jot down your recommendations, so we built in a Like button that sends a notification to the DJ when someone likes their track.

2: Music looks better with you

Many of your favorite songs have creative and beautiful music videos you might never have seen. I was personally a bit surprised to see the video for Big Data’s Dangerous

We first thought we would do Spotify-to-Spotify; you start a track in your Spotify, I hear it in mine. That idea is almost seven years old and started as a feature request for Spotify, placed on Jaiku (Twitter’s predecessor). But we can’t control the Spotify Mac app from the web, installing a Mac app just to listen would be too much work. Anyway, Last.fm has a really cool Spotify media bar which can actually control the Spotify Mac app, but it seems it’s some kind of a private beta test. So we took a leap of faith and began playing on Youtube.

We found two surprises. First, all the songs are there, in perfect quality and most of them with high quality videos. Second, we found ourselves watching all the videos for our favorite playlists. It’s like your own private MTV.

3: People think it’s illegal

When we got featured on Product Hunt (and our servers showed their appreciation by flatlining for four hours), another interesting trend began to rise among those who got in before the crash: many of them thought it was criminal. I guess all the pieces were just so much in sync that the illusion worked: That you are streaming music from your computer to mine, in great quality, with no delay. Obviously, we totally legally find the songs on Youtube and play them there, with banner ads and all. If you play a Nicki Minaj song for your one million listeners, she gets paid accordingly.

Here’s how to try right now

Go to twinjack.com and find a DJ who’s online right now. I’ve seen active DJs around the clock, and I already have a few favorites that have introduced me to bands I didn’t know before (like Big Data and their horror music video).

Or why don’t you just grab the app from the Mac AppStore and start playing music for your friends right now?

Your music will sound better with them.

(Oh, yes, and by the way, we built in a little easter egg, or tribute to a hero from the early days — if you use last.fm from your Sonos, Spotify, Rdio, Blackberry, you already have a Twinjack link! Replace bbc6music with your username in this link: www.twinjack.com/lastfm/bbc6music)