The concept of building a Digg for music has been tried before (see Contrastream or iJigg), but a music streaming site called thesixtyone is the closest I’ve seen so far to getting the formula right. It features only about 50,000 tracks self-uploaded by indie artists and music labels, but visitors can listen to the full stream of each track and vote their favorites up the rankings by hitting the “heart” button. The results are highly listenable playlists by genre, tag, or just what’s hot right now.

The key to making the site work, however, is not simply the Digg-like voting system. By now, that is becoming a pretty common feature (even the Hype Machine uses hearts) and is fairly easy to manipulate. The voting on thesixtyone is combined with some concepts learned from video games. Listeners cannot just indiscriminately heart up any song they want. They are given a limited number of heart points on a daily basis. More points can be earned for identifying good music early or recruiting friends to the service. Songs can only be given positive heart points, however. They can’t be demoted for being really bad. But the fact that the number of points are limited means in theory that only the most deserving songs will get enough to make it to the home page or the top of any given category.

Members also earn reputation points, and can level up as their reputation grows. The higher level a member achieves, the more hearts he or she can distribute. Reputation points are earned by hearting a song early before it becomes popular. Members also receive a portion of the reputation points earned by their friends. This rewards people with good taste in both music and friends.