Exposure of related artists and songs, Last.FM

[Jud Craft]

With Amarok 1.4, if I understood correctly, Last.FM was used for
identifying related artists, which let Amarok list suggested songs by
those artists (if those songs and artists were present in your
collection).  Being a database that crowdsources the relevant
connections, it was a handy way to retrieve them.

But there were a few problems with Amarok 1.4's use of Last.FM for this feature:

1.  It only retrieved a few at a time; and it refreshed the list of
related artists (and thus suggested songs) often.  This means that at
random, Amarok would refresh the list, and suddenly the Suggested
Songs list would change, or would disappear completely (if the new
retrieved Related Artists weren't in your library at all).
2.  Even though it linked to related songs that were available in your
collection, this functionality disappeared completely when offline
(even though the songs haven't -- we still have the content, we've
just lost the ability to connect it in context).

I'm not sure how Related Artists/Suggested Songs work in Amarok 2.0,
but I have a suggestion or two to combat these problems, which I
suspect are still present.

1.  Abstract the "related artists" and "suggested songs" away from
Last.FM -- this way, any service in the future could specify a
connection between songs.
2.  There should be a hidden mechanism which saves relevant
connections to the database -- only relevant connections; there's no
reason to save a song's entire Last.FM related artists/songs link if
the user's collection doesn't have any of these songs; only save the
ones that actually exist in the collection.
3.  So theoretically, whenever you play a song, Amarok will query from
the Related Artist/Song sources -- first from the internal copy in the
collection, and later from service providers, such as Last.FM.

The result is that related and suggested songs and artists is now
functionality that is available in Amarok, as opposed to only when
Last.FM is available.  If you're offline, a user will notice that he
can still view suggested songs and artists (for the media in his
collection -- artists and songs he doesn't have simply don't show up
offline -- no need to know about a reference if there's no way you can
access it).

In addition, since every related song/artist-connection (that is
present in the collection) is saved to the Amarok database itself,
you'll never experience problem #1 of the 1.4 Amarok:  Suggested Songs
won't suddenly disappear or change just because a different subset of
related artists of that song was retrieved; you'll always have access
to any previous related artist/song data that has been collected by
the database.

This way, you can still "rediscover your music" (in this context, view
novel connections between your songs that you may not have been aware
of before), even if you're not online.  It makes the user interface
and experience less inconsistent (information being available at one
point and suddenly gone the next).

In terms of displaying the Related artists/songs, Banshee 1.4 has a
very attractive way to do it:  they display them in a Recommendations
panel which has a very stylish layout of each song in a simple grid,
with information and a small cover art clip for each one -- mimicking
the smooth layout of the iTunes store.

I believe at the moment that a Plasma page is used to display the
Related Artists/songs in Amarok 2 (forgive me if that's incorrect).  A
catchy layout, as opposed to a simple list, is, well, eye-catching --
and it could be very functional if, for example, each entry linked to
a query in Magnatune or a page in Amazon to buy the album/download the
MP3 (if that song is not in the user's collection), leading to a very
cohesive experience.