Posts Tagged spotify

The Echo Nest Is Joining Spotify: What It Means To Me, and To Developers

I love writing music apps and playing with music data. How much? Every weekend I wake up at 6am and spend a long morning writing a new music app or playing with music data. That’s after a work week at The Echo Nest, where I spend much of my time writing music apps and playing with music data. The holiday break is even more fun, because I get to spend a whole week working on a longer project like Six Degrees of Black Sabbath or the 3D Music Maze.

That’s why I love working for The Echo Nest. We have built an amazing open API, which anyone can use, for free, to create music apps. With this API, you can create phenomenal music discovery apps like Boil the Frog that take you on a journey between any two artists, or Music Popcorn, which guides you through hundreds of music genres, from the arcane to the mainstream. It also powers apps that create new music, like Girl Talk in a Box, which lets you play with your favorite song in the browser, or The Swinger, which creates a Swing version of any song:

One of my roles at The Echo Nest is to be the developer evangelist for our API — to teach developers what our API can do, and get them excited about building things with it. This is the best job ever. I get to go to all parts of the world to attend events like Music Hack Day and show a new crop of developers what they can do with The Echo Nest API. In that regard, it’s also the easiest job ever, because when I show apps that developers have built with The Echo Nest API, like The Bonhamizer and The Infinite Jukebox, or show how to create a Pandora-like radio experience with just a few lines of Python, developers can’t help but get excited about our API.


Photo by Thomas Bonte

At The Echo Nest we’ve built what I think is the best, most complete music API — and now our API is about to get so much better.

spotify-logo-primary-vertical-light-background-rgbToday, we’ve announced that The Echo Nest has been acquired by Spotify, the award-winning digital music service. As part of Spotify, The Echo Nest will use our deep understanding of music to give Spotify listeners the best possible personalized music listening experience.

Spotify has long been committed to fostering a music app developer ecosystem. They have a number of APIs for creating apps on the web, on mobile devices, and within the Spotify application. They’ve been a sponsor and active participant in Music Hack Days for years now. Developers love Spotify, because it makes it easy to add music to an app without any licensing fuss. It has an incredibly huge music catalog that is available in countries around the world.

Spotify and The Echo Nest APIs already work well together. The Echo Nest already knows Spotify’s music catalog. All of our artist, song, and playlisting APIs can return Spotify IDs, making it easy to build a smart app that plays music from Spotify. Developers have been building Spotify / Echo Nest apps for years. If you go to a Music Hack Day, one of the most common phrases you’ll hear is, “This Spotify app uses The Echo Nest API”.

I am incredibly excited about becoming part of Spotify, especially because of what it means for The Echo Nest API. First, to be clear, The Echo Nest API isn’t going to go away. We are committed to continuing to support our open API. Second, although we haven’t sorted through all the details, you can imagine that there’s a whole lot of data that Spotify has that we can potentially use to enhance our API.  Perhaps the first visible change you’ll see in The Echo Nest API as a result of our becoming part of Spotify is that we will be able to keep our view of the Spotify ID space in our Project Rosetta Stone ID mapping layer incredibly fresh. No more lag between when an item appears in Spotify and when its ID appears in The Echo Nest.

The Echo Nest and the Spotify APIs are complementary. Spotify’s API provides everything a developer needs to play music and facilitate interaction with the listener, while The Echo Nest provides deep data on the music itself — what it sounds like, what people are saying about it, similar music its fans should listen to, and too much more to mention here. These two APIs together provide everything you need to create just about any music app you can think of.

I am a longtime fan of Spotify. I’ve been following them now for over seven years. I first blogged about Spotify way back in January of 2007 while they were still in stealth mode. I blogged about the Spotify haircuts, and their serious demeanor:

Those Crazy Spotify Guys in 2007

Those Crazy Spotify Guys in 2007

I blogged about the Spotify application when it was released to private beta (“Woah – Spotify is pretty cool”), and continued to blog about them every time they added another cool feature.

Last month, on a very cold and snowy day in Boston, I sat across a conference table from of bunch of really smart folks with Swedish accents. As they described their vision of a music platform, it became clear to me that they share the same obsession that we do with trying to find the best way to bring fans and music together.

Together, we can create the best music listening experience in history.

I’m totally excited to be working for Spotify now. Still, as with any new beginning, there’s an ending as well. We’ve worked hard, for many years, to build The Echo Nest — and as anyone who’s spent time here knows, we have a very special culture of people totally obsessed with building the best music platform. Of course this will continue, but as we become part of Spotify things will necessarily change, and the time when The Echo Nest was a scrappy music startup when no one in their right mind wanted to be a music startup will be just a sweet memory. To me, this is a bit like graduation day in high school — it is exciting to be moving on to bigger things, but also sad to say goodbye to that crazy time in life.

There is a big difference: When I graduated from high school and went off to college, I had to say goodbye to all my friends, but now as I go off to the college of Spotify, all my friends and classmates from high school are coming with me. How exciting is that!


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The Spotify Play Button – a lightening demo

Spotify just released a nifty embeddable play button. With the play button you can easily embed Spotify tracks in any web page or blog.  Since there’s really tight integration between the Spotify and Echo Nest IDs, I thought I’d make a quick demo that shows how we can use the Echo Nest playlist API and the new Spotify Play button to make playlists.

The demo took about 5 minutes to write (shorter than it is taking to write the blog post). It is simple artist radio on a web page.  Give it a go at:  Echo Nest + Spotify Play Button Demo

Here’s what it looks like.

Update: Charlie  and Samuel pointed out that there is a multi-track player too.  I made a demo that uses that too:

The Spotify Play button is really easy to use, looks great. Well done Spotify.



Syncing Echo Nest analysis to Spotify Playback

With the recently announced Spotify integration into Rosetta Stone, The Echo Nest now makes available a detailed audio analysis for millions of Spotify tracks.  This audio analysis includes summary features such as tempo, loudness, energy, danceability, key and mode, as well as a set of fine-grained segment features that describe details such as where each bar, beat and tatum fall and the detailed pitch, timbral and loudness content of each audio event in the song.   These features can be very useful for driving Spotify applications that need to react to what the  music sounds like – from advanced dynamic music visualizations like the MIDEM music machine or synchronized music games like Guitar Hero.

I put together a little Spotify App that demonstrates how to synchronize Spotify Playback with the Echo Nest analysis.  There’s a short video here of the synchronization:

video on youtube:

In this video you can see the audio summary for the currently playing song, as well as a display synchronized ‘bar’ and ‘beat’ labels and detailed loudness, timbre and pitch values for the current segment.

How it works:

To get the detailed audio analysis,  call the track/profile API with the Spotify Track ID for the track of interest. For example, here’s how to get the track for Radiohead’s Karma Police using the Spotify track ID:

This returns audio summary info for the track, including the tempo, energy and danceability.  It also includes a field called the analysis_url  which contains an expiring URL to the detailed analysis data. (A very abbreviated excerpt of an analysis is contained in this gist).

To synchronize Spotify playback with the Echo Nest analysis we need to first get the detailed analysis for the now playing track.  We can do this by calling the aforementioned track/profile call to get the analysis_url for the detailed analysis, and then retrieve the analysis (it is stored in JSON format, so no reformatting is necessary).  There is one technical glitch though.  There is no way to make a JSONP call to retrieve the analysis. This prevents you from retrieving the analysis directly into a web app or a Spotify app.  To get around this issue, I built a little proxy at that supports a JSONP style call to retrieve the contents of the analysis URL.  For example, the call:

will return the analysis json wrapped in the foo() callback function.  The Echo Nest does plan to add JSONP support to retrieving analysis data, but until then feel free to use my proxy. No guarantees on support or uptime since it is not supported by engineering. Use at your own risk.

Once you have retrieved the analysis you can get the current bar, beat, tatum and segment info based upon the  current track position, which you can retrieve from Spotify with:    sp.getTrackPlayer().getNowPlayingTrack().position.  Since all the events in the analysis are timestamped, it is straightforward to find a corresponding bar,beat, tatum and segment given any song timestamp.  I’ve posted a bit of code on gist that shows how I pull out the current bar, beat and segment based on the current track position along with some code that shows how to retrieve the analysis data from the Echo Nest.  Feel free to use the code to build your own synchronized Echo Nest/Spotify app.  

The Spotify App platform is an awesome platform for building music apps.  Now, with the ability to use Echo Nest analysis from within Spotify apps,  it is a lot easier to build Spotify apps that synchronize to the music. This opens the door to a whole range of new apps. I’m really looking forward to seeing what developers will build on top of this combined Echo Nest and Spotify platform.


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Writing an Echo Nest + Spotify App

Last week The Echo Nest and Spotify announced an integration of APIs making it easy for developers to write Spotify Apps that take advantage of the deep music intelligence offered by the Echo Nest. The integration is via Project Rosetta Stone (PRS).  PRS is an ID mapping layer in the API that allows developers to use the IDs from any supported music service with the Echo Nest API.   For instance, a developer can request via the Echo Nest playlist API a playlist seeded with a Spotify artist ID and receive Spotify track IDs in the results.

This morning I created a Spotify App that demonstrates how to use the Spotify and Echo Nest APIs together. The app is a simple playlister with the following functions:

  • Gets the artist for the currently playing song in Spotify
  • Creates an artist radio playlist based upon the now playing artist
  • Shows the playlist, allowing the user to listen to any of the playlist tracks
  • Allows the user to save the generated playlist as a Spotify playlist.
The app is functional, but not very pretty. Here’s a screenshot:

The entire app, including all of the HTML, CSS and JavaScript, is 150 lines long.I’ve made all the code available in the github repository SpotifyEchoNestPlaylistDemo.    Here are some of the salient bits. (apologies for the screenshots of code. has poor support for embedding sourcecode. I’ve been waiting for gist embeds for a year)

makePlaylistFromNowPlaying() – grabs the current track from spotify and fetches and displays the playlist from The Echo Nest.

fetchPlayst() – The bulk of the work is done in the fetchPlaylist method.  This method makes a jsonp call to the Echo Nest API to generate a playlist seeded with the Spotify artist.  The Spotify Artist ID needs to be massaged slightly. In the Echo Nest world Spotify artist IDs look like ‘spotify-WW:artist:12341234’ so we convert from the Spotify form to the Echo Nest form with the one liner:

  var artist_id = artist.uri.replace('spotify', 'spotify-WW');

Here’s the code:

The function createPlayButton creates a doc element with a clickable play image, that when clicked, calls the playSong method, which grabs the Spotify Track ID from the song and tells Spotify to play it:

Update: I was using a deprecated method of playing tracks. I’ve updated the code and example to show the preferred method (Thanks @mager).

When we make the playlist call we include a buckets parameter requesting that spotify IDs are returned in the returned tracks. We need to reverse the ID mapping to go from the Echo Nest form of the ID to the Spotify form like so:

Saving the playlist as a spotify playlist is a 3 line function:

Installing and running the app

To install the app, follow these steps:

  • make sure you have a Spotify Developer Account
  • Make a ‘playlister’ directory in your Spotify apps folder (On a mac this is in ~/Spotify/playlister)
  • Get the project files from github
  • Copy the project files into the ‘playlister’ directory. The files are:
    • index.html – the app (html and js)
    • manifest.json – describes your app to Spotify.  The most important bit is the ‘RequiredPermissions’ section that lists ‘http://*’. Without this entry, your app won’t be able to talk to The Echo Nest.
    • js/jquery.min.js – jquery
    • styles.css – minimal css for the app
    • play.png – the image for the play button
    • icon.png – the icon for the app

To run the app type ‘spotify:app:playlister’ in the Spotify search bar. The app should appear in the main window.

Wrapping Up

Well, that’s it – a Spotify playlisting app that uses the Echo Nest playlist API to generate the playlist.  Of course, this is just the tip of the iceberg. With the Spotify/Echo Nest connection you can easily make apps that use all of the Echo Nest artist data:  artist news, reviews, blogs, images, bios etc,  as well as all of the detailed Echo Nest song data: tempo, energy, danceability, loudness, key, mode etc.  Spotify has created an awesome music app platform. With the Spotify/Echo Nest connection, this platform has just got more awesome.

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Boil the Frog – the unreleased Spotify Version

Update – You are probably looking for this web-based version of Boil The Frog and the blog post about it.

Screenshot 1:2:13 5:54 AM-3

The rest of this article is about the unreleased Spotify Version of Boil the Frog.

I’m at Music Apps Hack Weekend doing my favorite thing: hacking on music. I’ve just finished my hack called Boil the Frog.  Boil the Frog  is a Spotify App that will create playlists that gradually take you from one music style to another.  It is like the proverbial story of the frog in the pot of water. If you heat the water gradually, the frog won’t notice and will happily sit in the pot until it becomes frog stew.  With Boil the Frog  you can do the same thing musically.  Create a playlist that gradually takes your pre-teen from Miley Cyrus to Miles Davis, or perhaps more perversely the Kenny G fan to Cannibal Corpse.

To build the app I built an artist similarity graph of 100,000 of the most popular artists. I use The Echo Nest artist similarity to connect each artist to its four nearest neighbors. To find the path between any two artists I use a bidirectional Dijkstra shortest path algorithm.  Most paths can be computed in less than 100ms.

The Spotify Apps API is the perfect hacking platform. You can build a Spotify app that has full access to the vast Spotify music catalog and artwork, along with access to the listener’s catalog.   Since the Spotify Apps run in an embedded browser all of your web app programming skills apply.  You can use jQuery, make calls to JSON APIs, use HTML 5 canvas. It is all there. Spotify has done a really good job putting together this platform.  The only downside is that, unlike the web, it is hard to actually release Spotify apps, but the Spotify team is working to make this easier.    I’d love to release Boil the Frog because it is really fun to make playlists that bring you from one music style to another. It is interesting to see what musical neighborhoods you wander through on your way.  For instance, I made a Kenny G to Cannibal Corpse playlist. To get there, the playlist brought me from easy listening, to movie soundtracks and then through video game soundtracks to get to the heavy metal world.  Cool stuff.  If you want to see a playlist between two artists let me  know in the comments and I’ll create and share the playlist with you.

I made a video of Boil the Frog in action.   Check it out:


Update: I’ve just pushed the client code out to github:

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The Future of Mood in Music

One of my favorite hacks from Music Hack Day London is Mood Knobs.  It is a Spotify App that generates Echo Nest playlists by mood. Turn some cool virtual analog knobs to generate playlists.

Mood Knobs

The developers have put the source in github. W00t.  Check it all out here: The Future of Mood in Music.

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My Music Hack Day London hack

It is Music Hack Day London this weekend.  However, I am in New England, not Olde England, so I wasn’t able to enjoy in all the pizza, beer and interesting smells that come with a 24 hour long hackathon.  But that didn’t keep me from writing code. Since Spotify Apps are the cool new music hacking hotttnesss, I thought I’d create a Spotify related hack called the Artist Picture Show. It is a simple hack – it shows a slide show of artist images while you listen to them. It gets the images from The Echo Nest artist images API and from Flickr.  It is a simple app, but I find the experience of being able to see the artist I’m listening too to be quite compelling.

Slightly more info on the hack here.


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