Yes, because there is no support for Last.fm in the sidebar tab yet. I can easily write a patch for that, but I don't know if this is the wanted behavior. Can you ask the mailing list / forum / IRC if this should be added? If yes, the coding is the easiest part

Well, at present, the code and the documentation are at odds with each other. They should at least be consistent one way or another prior to a decision being made...

The documentation that is presently seemingly incorrect is both the message presented to users on the "Add URL Relationship" edit page:

http://musicbrainz.org/edit/relationship/create_url?entity=4279aba0-1bde-40a9-8fb2-c63d165dc554&type=artist

selecting "has a social networking page at" type the following message is displayed:

"This link is used to associate an artist or label with their page on a social networking site such as Facebook or Last.fm. (Details)"

and the Details link is to http://musicbrainz.org/doc/Social_Networking_Relationship_Type
which says:

"This link is used to associate an artist or label with their page on a social networking site such as Facebook or Last.fm. "

If you don't want to support Last.fm in the sidebar tab then don't tell users they should provide this information!

As hrglgrmpf said, "there is no support for Last.fm in the sidebar tab yet." It only shows under the "Relationships" tab.

If some user told you not to link to last.fm, then he's wrong - as are the ominous users who had told him the same before.

OK, so no decision required. Just fix the code.

There is still a decision required of whether or not we want to have Last.FM in the sidebar

Hmm, well, yes, sort of. It is still not decided if we want Last.fm links in the sidebar. I don't know who should decide this (definitely no RFC ).

Actually, I have the following in mind:
Since most last.fm names are just http://www.last.fm/music/<NAME_OF_ARTIST>, we could display this by default, and only enter an URL AR if for some reason (e.g. unicode punctuation) the MB name differs from the Last.fm name, e.g.: http://musicbrainz.org/edit/14935191

This could be done as user-script or as configurable option. What do you think? I find it a bit a waste of all our time to enter all those last.fm names, when a computer can do the same .

As far as I remember http://last.fm/music/artist instead will auto-redirect to proper language instead of only english, fresh cookie-less browser session (can't test now, it's been blocked by firewall).

One of the other problems of Last.fm is that they have multiple pages for the same artist and they can't make their mind up on how they want to collate them. So how would this work for e.g. Greek artists?

http://musicbrainz.org/artist/457a3e37-cbf5-41f5-8c0a-b6f20a2ed905
http://www.last.fm/music/George%2520Dalaras
http://www.last.fm/music/%CE%93%CE%B9%CF%8E%CF%81%CE%B3%CE%BF%CF%82+%CE%9D%CF%84%CE%B1%CE%BB%CE%AC%CF%81%CE%B1%CF%82

Getting back to the issue of this ticket though... I consider it very weird that both Facebook and Last.fm are mentioned as examples of "social networking page" URL relationships, when only the former is supported by the sidebar. Seems like these two decisions were not made jointly, resulting in confusion for this user at least... either you want Last.fm artist page URL relationships or you don't, if you do, then I believe it should be supported in the sidebar with equal precedence to Facebook. If you think Facebook belongs in the sidebar but not Last.fm, then it's weird to even mention Last.fm alongside Facebook in the documentation. But that's just my opinion...

Yes, you are right... if it is mentioned in the same sentence (equally), it should also be on the sidebar. There was a post regarding Last.fm artist links on the mailing list a few weeks ago, but it had no responses...

I have the following opinion: Allow all Last.fm links, as long as the link provides useful content there (a biography, etc.). I wouldn't even exclude pages with multiple artists. So what? Last.fm often contains biographies for all the artists with the same name, so the links are not semantically wrong at all.

We also link to the same wikipedia page for performance names...

In your example, I would pick the most popular entry (the one with the most content), and use Last.fm's "suggest correction" feature, so that they will be merged at some point in the future...

Issues regarding which of the last.fm URLs to choose/add/allow (or all of them) as ARs are issues for the Style mailing list to consider with respect to the relationship type and its wiki documentation, not the bug tracker. This is not really the appropriate place to discuss those aspects.

This ticket represents the Data Display issue. The external links are convenience links to make the data display friendlier; they do not represent the entirety of what the community has decided is useful to collect. Moreso, the URLs are part of the data set that other systems may choose to use. What MB decides to put in the External Links is neither here nor there when making a decision on which data is useful to collect/link.

The "documentation" gives two possible social networking page options; but I don't really see a reason to expect it to be consistent across different AR types; especially when the AR in question is generic in nature.

LastFM supports (although it's not really publicized) http://www.last.fm/mbid/457a3e37-cbf5-41f5-8c0a-b6f20a2ed905 that redirects to the URL with the artist name.

That's personally the only way I want MB to link (automatically) to LastFM.
I don't see the point of maintaining manually the mapping.

Last.fm have a very incomplete usage of our MBIDs, I don't think that's a very good idea (at the moment)

@voiceinsideyou: sorry for abusing the bug tracker for unrelated discussions. Back to the original topic:
1. [ ] Last.fm links in the sidebar
2. [ ] Last.fm links not in the sidebar

I would vote for (1.). What kind of decision process is required for this?

I vote for (1.) too. The problem with multiple links surely can't be any worse than for different languages of Wikipedia pages, right? :/

Sorry for not voting 1 or 2 right away : I'd like to see the official list (or piece of code) of what's included and what's not.

Thanks murdos for your mbid link, I've added it to my userjs.
I've made a userjs that adds all the missing links from Relationships tab into side bar.

Official list of the sidebar links? Nothing easier than that:

Supported sidebar links:
https://github.com/metabrainz/musicbrainz-server/blob/master/lib/MusicBrainz/Server/Data/URL.pm#L14

Supported sidebar icons:
https://github.com/metabrainz/musicbrainz-server/blob/master/root/static/styles/layout.css#L380

@patate12: Your userjs works brilliant, thanks a lot! This is exactly what I searched for!
EDIT: Maybe you can add BBC (if the link is not already there)? That would be perfect !

I submitted a small patch for review:
http://codereview.musicbrainz.org/r/1444/

The list of URLs that appear in the sidebar is:

ollie@deimos ~/Work/MusicBrainz/mb_server (next*) % ack -l 'Sidebar' lib/MusicBrainz/Server/Entity/URL | sort | uniq
lib/MusicBrainz/Server/Entity/URL/Allmusic.pm
lib/MusicBrainz/Server/Entity/URL/ASIN.pm
lib/MusicBrainz/Server/Entity/URL/BBCMusic.pm
lib/MusicBrainz/Server/Entity/URL/CDBaby.pm
lib/MusicBrainz/Server/Entity/URL/Discogs.pm
lib/MusicBrainz/Server/Entity/URL/Facebook.pm
lib/MusicBrainz/Server/Entity/URL/IBDb.pm
lib/MusicBrainz/Server/Entity/URL/IMDb.pm
lib/MusicBrainz/Server/Entity/URL/InternetArchive.pm
lib/MusicBrainz/Server/Entity/URL/Jamendo.pm
lib/MusicBrainz/Server/Entity/URL/LyricWiki.pm
lib/MusicBrainz/Server/Entity/URL/MetalArchives.pm
lib/MusicBrainz/Server/Entity/URL/MusicMoz.pm
lib/MusicBrainz/Server/Entity/URL/MySpace.pm
lib/MusicBrainz/Server/Entity/URL/PureVolume.pm
lib/MusicBrainz/Server/Entity/URL/Sidebar.pm
lib/MusicBrainz/Server/Entity/URL/Twitter.pm
lib/MusicBrainz/Server/Entity/URL/VGMdb.pm
lib/MusicBrainz/Server/Entity/URL/Wikipedia.pm
lib/MusicBrainz/Server/Entity/URL/YouTube.pm

I vote for this ticket with the hope that we would eventually someday display not only ALL URL but all URL and their dates (included in my temporary userjs).