Last.fm API Summary
in under 2 minutes

David Whiting
Music Tech Fest Hack Camp - 18th May 2011

Last.fm API is great for hacks because...

• We have 64 billion music listening data points (scrobbles) about 43 million users
• We know how tracks and artists are related to each other by people's listening habits
• We know about hundreds of thousands of gigs and festivals
• We have over 14 million streamable tracks available via our radio service
• We have images, metadata and bio info for millions of artists

Public API

Last.fm Public API

HTTP webmethods to access catalogue, events, charts and recommendations.

• GET or POST in, JSON or XML back
• Cross-site enabled, or JSONP via "callback=..."
• Requires api key (free and instant to get one)
• Public data requires no authentication
• Private data an write operations via authed access
• Fully documented (almost) at www.last.fm/api

Examples

Get information about the artist "Demoscene Time Machine":
To do this:

artist.getinfo({
    artist:  "Demoscene Time Machine",
    api_key: "202ece1f999e55ce1c3aaabbbad6ae40",
    format:  "json"})

We need to hit this URI:
http://ws.audioscrobbler.com/2.0/?method=artist.getinfo&artist=Demoscene+Time+Machine&api_key=202ece1f999e55ce1c3aaabbbad6ae40&format=json

Examples

Get the current hyped track chart:
http://ws.audioscrobbler.com/2.0/?method=chart.gethypedtracks&api_key=202ece1f999e55ce1c3aaabbbad6ae40&format=json

Get the current top "electro house" artists:
http://ws.audioscrobbler.com/2.0/?method=tag.getweeklyartistchart&tag=electro+house&api_key=202ece1f999e55ce1c3aaabbbad6ae40&format=json

JQuery example

$.get(
  "http://ws.audioscrobbler.com/2.0/?",
  {
    method:  "chart.gethypedtracks",
    api_key: "202ece1f999e55ce1c3aaabbbad6ae40",
    format:  "json"
  },
  function(response) {
    // do something useful with response here
  }
});

Radio stations

Radio

• Last.fm radio is defined by RQL (Radio Query Language) queries.
• You can listen to them with existing clients, or write your own.
• Use it to create streaming radio stations from combinations of parameters

Radio Query Language (RQL)

How to play

Base64 encode it, then insert in the URL "lastfm://rql/{base64encodedRQL}"

If you have a Last.fm client installed, opening this link will play your radio station

This URL is also a valid input to the radio.tune() API method (if you want to write your own client)

Real-time data

Cyclone - Shiny brand new (experimental) realtime data API

var q2 = new lfmc_TopFeed('track')
.setSize(5)
.onData(function(list) {
    //present list data here
});
        

Cyclone - full details at http://hackdaynode.last.fm

Prizes

• Last.fm subscriptions
• Big bag o' merch
• Tickets to next Last.fm presents event

If you need help:

• Find me and ask me stuff
• Twitter: @dawhiting
• IRC: #musictechfest on Freenode