About Digger

Digger began in late 2020 as a project to categorize music for contextual retrieval, where a context is defined as any listening situation you might otherwise create a playlist for. The idea was to take a myriad of contexts, factor out the common elements, and support autoplay without having to make playlists. The belief this was possible grew out of the SlideMatch project in 2009, which used 10 scalar characterizations to match music for retrieval. The challenge for Digger was to create similar retrieval power with far fewer song data requirements.

By combining dual scalar values with well chosen keywords, Digger was able to achieve substantial retrieval power. For example Instead of playlists for "Brunch", "Beach", "Dinner", "Party" and such, a single "Social" keyword combined with energy level and approachability filtering provides equivalent or better access. Retrieval processing prefers what was least recently played, so it digs through all matching songs in the least boring order. Digger was initially tested on a diverse collection of 10k+ songs to verify the rating process was reasonable and contextual retrieval worked well.

Album listening

Digger was created to effortlessly play appropriate music without selection fatigue. While autoplay is fantastic for an enormous range of listening situations, listening to an album is still probably the best way to fully appreciate a song in the context of a music release.

Select album view anytime to switch to playing the album.

Digger song ratings in action

In addition to retrieval, song ratings make it easy to describe your impression to others:

Sharing a song copies the Title, Artist, Album, Keywords, Approachability and Energy Level, together with your comment into a single statement to send however you like.


Initially created as a mechanism to synchronize Digger data across devices using only bare minimum personal information, DiggerHub now also provides for structured collaboration that respects your time and energy.


Find friends and music fans by their Digger name. If you haven't added any friends yet, and you want to get a feel for how things work, you can click "Connect Me" to add whoever the hub picks for you.


See how much music you have in common. If you have songs in your collection that you haven't rated yet, your friends provide default rating information you can use for contextual retrieval. The "rcv" tab shows how many default ratings you've received. The "snd" tab shows how many default ratings they have received from you. If you remove a friend, their default ratings are also removed. When you play a song, any default rating information for that song becomes yours.


See what your friends have shared recently and get automatic recommendations from your friends matching your current listening parameters.

More info

The Digger project, mobile platform apps, and DiggerHub are all OPENSOURCE. For more information, visit the project site issues and other details.