TuneGlue is a force-directed graph exploring relationships between artists based on the Last fm database and amazon.co.uk. There's no much more information at this time about TuneGlue, in what seems to be an initial beta version.You basically start by inputting an artist name and then you can build your network from there, by expanding each individual node (representative of an artist/band) and dragging them on screen. One can also explore all albums from each artist on the spot and link out to amazon.com to buy any of them.
