What's cooking in the Last.fm playlisting lab

Thursday, 27 September 2012
by mark
filed under About Us
Comments: 47

In the Music Information Retrieval team here at Last.fm we’re currently developing a new generation of smart playlisting engines, and we’d like take the chance to give you a sneak preview of what they can do, as well as explaining a bit more about playlisting services in general.

You can think of playlisting engines as falling into two categories: one repeatedly chooses which track to stream next when you’re listening to an internet radio station like any of Last.fm’s radio stations; the other selects a single set of tracks from a collection all in one go, like iTunes genius or Google Music’s instant mix. While in theory these do similar jobs, as every good scientist knows, the difference between theory and practice is greater in practice than it is in theory, and in practice the requirements for these two types of playlists can be very different. Our new generation service is designed to provide instant playlists from collections of any size, and you can try a demo right now, or read on to find out more.

Last.fm instant playlisting

We’ll talk a bit more about radio playlisting in a separate post, but one of the main characteristics required from the other type of engine is the ability to choose from music collections of wildly varying sizes. Our existing engines have mostly been targeted at very large commercial catalogues containing millions of recordings – you can see them at work in the Last.fm Spotify app (start playing any track, go to the Now Playing tab in the app and click “Similar Tracks Playlist”).

The new generation of engines is designed to continue to do a really good job when choosing tracks from small personal collections. In practice that means we can’t rely on any single type of information to tell us which other tracks might be a good match for any particular playlist. Luckily thanks to your scrobbles and tags, and a bit of audio analysis and machine learning magic on our side, we have three independent types of information linking artists and tracks. Another new feature is the ability to generate playlists based on mood and other musical properties. Finally when playlisting from personal collections we’ve been able to experiment with ways of choosing the sequence of tracks that aren’t restricted by licensing rules.

But we know we still have a huge amount to learn before any machine can approach the skill of a human DJ, so we’ve built a simple demo to let you try out the services. Please let us know how you think we’re doing and we’ll incorporate your feedback into our final version of the new engines. Thanks for listening!


  1. Naglis
    27 September, 18:12

    This sound awesome. Thanks!

    A question:
    Will this engine be available through API? If yes, would it work only according to your scrobbles or, lets say, for a given collection of songs, too?

    Naglis – 27 September, 18:12
  2. mdotbb
    28 September, 00:20

    I love it. I hope I can export these to iTunes somehow. Or let me generate them in the iPhone app using music on my device.

    mdotbb – 28 September, 00:20
  3. Mark Levy
    28 September, 10:31

    @Naglis @mdotb yes indeed, the new service is designed to be able to target collections on any kind of device – we’re only using scrobbles here as an example, so that any Last.fm user can have a play. You’ll have to watch this space for news about how and when you can actually try them out on your own music.

    Mark Levy – 28 September, 10:31
  4. Tecfan
    28 September, 11:07

    Sad playlist was totally off, but the others were good. Tennis, Housse de Racket and Young Magic are not sad :)

    Tecfan – 28 September, 11:07
  5. Adam
    1 October, 14:42

    Most of mine came out well, except for ‘Strong Dance Beat’. Whilst I listen to alot of EDM, it picked blink-182, Four Year Strong, Deadmau5 and A Day To Remember.

    Still, great feature.

    Adam – 1 October, 14:42
  6. mance
    1 October, 17:33

    Ok, Thank

    mance – 1 October, 17:33
  7. Marie
    1 October, 18:48

    Will we be able to scrobble those playlists? It seems to be a good idea.

    Marie – 1 October, 18:48
  8. acane
    2 October, 00:57

    I like it, the playlists are intersting

    acane – 2 October, 00:57
  9. acane
    2 October, 00:59

    I like it, the playlists are intersting.


    acane – 2 October, 00:59
  10. jmouse
    2 October, 03:35

    I’m disappointed. I cannot listen to my playlist. At the time subscribed, i just clicked play and it did. Now you want me to scrobble…please. why? play, stop, etc are so simple, why complicate it?

    jmouse – 2 October, 03:35
  11. dress up games
    2 October, 11:38

    It takes a lot of hard work for your music to be recognized, especially if you are a new or an upcoming artist.

    dress up games – 2 October, 11:38
  12. Sanskar
    3 October, 05:25

    Love this idea

    Sanskar – 3 October, 05:25
  13. gscossy
    3 October, 23:07

    i am unhappy not being able to import my playlists from groove shark that was the reason i chose last.fm

    gscossy – 3 October, 23:07
  14. John Michael
    4 October, 08:24

    I like it very much….playlist is really interesting

    John Michael – 4 October, 08:24
  15. NyuuuuSaaaan
    4 October, 17:37

    Not bad, but I’d prefer if it moved from style to style more smoothly. It just jumps around far too much for me to listen to it. Then again, I’m sure that’s exactly what some people are looking for so it’d be great if we could choose how much variety we’d like.

    NyuuuuSaaaan – 4 October, 17:37
  16. Mark Levy
    4 October, 17:41

    @Marie this is just a demo, but you’ll certainly be able to scrobble from the applications we’re working on.

    @Adam thanks for the feedback, we’ve done a lot of work to improve the machine tags in the last few days and we’re currently testing the results.

    Mark Levy – 4 October, 17:41
  17. Duy Khánh
    5 October, 02:56

    I love it. I hope I can export these to another OS for smartphone somehow.

    Duy Khánh – 5 October, 02:56
  18. Bogdan
    6 October, 07:04

    It’s good, very good. Will they be available for android as well?

    Bogdan – 6 October, 07:04
  19. Rosiroo
    6 October, 12:32

    I absolutely LOVE this idea- would prefer to be able to listen in this fashion on your site rather than migrating to Spotify, so this is great news. Just tried out the Lounge playlist and I thought it was spot on.

    Rosiroo – 6 October, 12:32
  20. Marvin Weiss
    6 October, 13:35

    Maybe I’m among a small group of listeners, but I prefer listening to my choice of music only. I don’t want to hear other kinds of music at any time. My music is opera and operatic singers.
    I don’t understand why you end my music after a few minutes. How do I change that, if I can, to prevent any stops.
    Why have you changed your operations? Is that a message to chase me away?
    Please tell me what you are trying to do?

    Marvin Weiss – 6 October, 13:35
  21. Robert Bishop
    8 October, 05:11

    “Another new feature is the ability to generate playlists based on mood and other musical properties”

    That is so cool. How do you know what the “mood” of a track is though?

    Playlists on other musical properties sounds cool, like a playlist with long instrument solos, or all tracks over 9 min long. SO many cool options and ideas there.

    Robert Bishop – 8 October, 05:11
  22. sepp
    8 October, 13:26

    Doesn’t work for me. Tells me that I have to log in. I am logged in. ??

    sepp – 8 October, 13:26
  23. westher
    8 October, 18:28

    Am slightly surprised to find Howlin’ Wolf in a ‘sad’ playlist.

    Also, every other playlist seems to include Shania Twain. Probably because that’s one of the most mainstream artists I’ve been listening to these last 1000 tracks.

    westher – 8 October, 18:28
  24. westher
    8 October, 18:30

    Am slightly surprised to find Howlin’ Wolf in a ‘happy’ playlist.

    Also, every other playlist seems to include Shania Twain. Probably because that’s one of the most mainstream artists I’ve been listening to these last 1000 tracks.

    westher – 8 October, 18:30
  25. AdriaNnLA
    8 October, 21:39

    Poor confused robot.

    I have to wonder sometimes if I and your robot have sampled the exact same snippet in order to come to our categorical conclusions?

    Often, as is the case with “clean” vs. “distorted” and several others; we’re basically looking (or listening) for the presence (or absence) of a particular feature.

    Is there distortion? Yes – OK, distorted. No – OK, clean.

    However, it is always possible that within the track as a whole, their exist “distortion” that did not manifest in the short sample presented to human ears.

    I’ve also noticed a few tracks with intros come through in my comparisons, where the intro is completely incomparable to the remainder of the track.

    Perhaps another option to vote to have that particular track re-sampled? i.e. discard that snippet and procure another further in.

    AdriaNnLA – 8 October, 21:39
  26. Karsh
    9 October, 02:06

    Great stuff!! Hope you can integrate this into the mobile app, and also, allow exporting playlists to something like… xml files?


    Karsh – 9 October, 02:06
  27. Carol
    11 October, 03:03

    Does this mean there is once more a free app for Last.fm?

    Carol – 11 October, 03:03
  28. K1MO
    13 October, 13:58

    how should we test this properly with 30s previews? thats no listening experience. it’s like shopping .. i hate shopping :P

    K1MO – 13 October, 13:58
  29. tarots gratuit
    15 October, 10:19

    Congratulations on this excellent work and for giving us the opportunity to ‘hang out’ smart!

    tarots gratuit – 15 October, 10:19
  30. pcockey
    15 October, 14:11

    Most of this was pretty good, but it may be advisable to drop some of the “mood” playlists if nothing fits; I’ve been listening to a lot of doom metal lately and my “happy” playlist is hilarious.

    pcockey – 15 October, 14:11
  31. Mark Levy
    15 October, 14:50

    @pcockey we’ve actually made some improvements recently and I checked out your playlists in a new version that we’re testing – I’m glad to say that the “happy” playlist has disappeared. We’ll put this version live for everyone once we’re sure that it’s always better.

    Mark Levy – 15 October, 14:50
  32. Kevin
    15 October, 17:03

    I believe the scrobbling feature should be looked at again. Listening to a lot of black metal, I’ve been getting bands that arent even related to metal. The band Mayhem is a good example of this, it features techno artists that are similar to Mayhem which is anything but.

    Kevin – 15 October, 17:03
  33. najeeb
    16 October, 20:31

    Had an idea for the last.fm app for android. Perhaps an addon for the players or something. I’m not sure of the how, so let me get to the what:
    last fm can associate similar artists right, say i play shinedown, i also get thoery of a deadman for example. or i play bnl and i get hootie and the blowfish.
    well hows about when im playing music from my own collection on my android, last fm can automagically make a playlist out of similar artists out of the music collection i actually have. So i can put on shinedown and theory of a deadman, rev theory, alter bridge, adelita’s way will all come up.

    najeeb – 16 October, 20:31
  34. Lachlan
    18 October, 01:10

    It looks like it works pretty well. I can imagine that there would be quite a lot fo work involved in developing something like this.

    I didn’t find anything in particular that I thought was ‘wrong’ so I think you guys must be on the right track.

    Lachlan – 18 October, 01:10
  35. Greggo-Sanders
    18 October, 18:16

    Will this feature be free, or will it only be available to Last.fm subscribers?

    Greggo-Sanders – 18 October, 18:16
  36. Thomas
    19 October, 10:33

    Whoa…cool! Playlists that can actually play. What an innovation! I wonder if it’ll ever get past the 30-second sample stage…

    I suppose it’ll involve getting a “premium” subscription. But what the heck, I love chasing dangling carrots.

    Thomas – 19 October, 10:33
  37. isabela
    21 October, 18:01

    Hi, I’m very upset with this site, lastfm. I’ve been trying to recover my password since July this year and so far nothing!

    I can not receive any kind of attention of the administrators of this site. My account is from 2005 and I had been using irregularly, iis very annoying to lose something, for lack of attention of the administrators. I can not receive an e-mail password recovery! if anyone can help me, i_beeton@yahoo.com.br
    Thank you in advance.

    isabela – 21 October, 18:01
  38. frankus
    22 October, 00:07

    I like smart playlisting engines,nice work keep it up!

    www.franklinsmusic.com (sheet music selling & exchange)

    frankus – 22 October, 00:07
  39. Jason
    25 October, 07:15

    This shit cool,, I like it

    Jason – 25 October, 07:15
  40. Michael
    25 October, 15:39

    Sounds like a cool engine.

    Michael – 25 October, 15:39
  41. Sam
    26 October, 20:54

    I like it, but it would be better with a higher range than the last 1000 tracks. Perhaps an option for overall. It’s a really cool idea though!

    Sam – 26 October, 20:54
  42. Anon
    29 October, 20:37

    Pretty good for the most part, except for ‘Sad’. If you asked me what are the happiest bands I listen to, at least three of those bands showed up in that playlist (and I have a lot more sad music than happy music).

    Anon – 29 October, 20:37
  43. Dendyz Olivia
    31 October, 17:27

    Is the song/music only belongs to the moneyed? or simply belonging to descendants of musicians/singers before? or music/song belongs only trace their usual/emulate? where is the creativity/artistry us? where we will share? and where we can share without any element of taking advantage of the songwriter or imitate the far abroad. times have changed the media’s broad enough to open the shared media browsing we can tell if the song / music is original or the result of the work of the person in duplicate, let us be creative with the work itself and of the ideas of our own that art can be appreciated

    Dendyz Olivia – 31 October, 17:27
  44. Harry Lewis
    2 November, 06:15

    I love last fm radio

    Harry Lewis – 2 November, 06:15
  45. thomas/dextroustc
    7 November, 05:11

    pretty cool

    thomas/dextroustc – 7 November, 05:11
  46. Rafi B.
    8 November, 10:51

    I have a premium subscription and I can only hear 30 seconds previews of the instant playlist songs…

    Last.fm also removed “My Loved Tracks” radio for subscribers.

    Remind me again why am I paying for last.fm subscription?

    Rafi B. – 8 November, 10:51
  47. karim
    8 November, 12:56

    this is the last moment that i can stop fine best online radio..found it with last.fm

    karim – 8 November, 12:56

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