Products / 2026 / Live in the browser
MoodMix Lab
Set four mood sliders and get a playlist you can see the reasoning behind, with a short preview that sounds like each track's mood.
01
The problem
Recommendation engines hide their logic behind a black box.
02
How I approached it
Each track has an energy, focus, chill and joy signature, and the match is 100 minus the mean distance to your sliders, shown next to every track. Discovery mode trades score for artists you have not heard yet, and energy ramp keeps the best matches but plays them calm to lively, the smooth transitions playlist research favours. Previews are short arpeggios built from the cues music emotion studies find strongest (Gabrielsson and Lindström 2010): major or minor from joy, tempo from energy, a softer timbre when chill.
03
The outcome
Recommendations you can inspect and argue with. Scoring, discovery, the energy ramp and previews are unit tested under Node.
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