It's just an embedded plugin; I don't think you need to consider it a threat. It will work in some browsers and not others. I can't see it affecting midi settings.

So far as I know, the verb "to scrobble" was coined by John Masefield; see his children's book The Box of Delights: Or, When the Wolves Were Running (1935) for usage. It basically meant "to scoop up, abduct, kidnap"; evidently it has acquired some newer meanings via the web.  http://www.urbandictionary.com/  gives: "When Last.fm automatically sends the name of each song played by audio player, they call this 'scrobbling.' [example] 'The application will scrobble your playlist.'