How to filter song artist

Hi,

Is there a "unique artist" filter on the song API? For example, the response of the request below is showing duplicate records. I know that the duplicate records was caused of the song ID, but is it possible to show only one song regardless of its version?

http://developer.echonest.com/api/v4/song/search?api_key=XXXXXXXXXX&bucket=artist_location&bucket=audio_summary&bucket=id:7digital-US&callback=angular.callbacks._0&format=jsonp&limit=true&results=5&sort=song_hotttnesss-desc&title=killing+in+the+name+of

Thanks in advance!