Introducing MusicSeed

Smart playlists are dead. Keep the mood up.

You know the moment. You’re in the middle of a conversation and somebody drops a track — and just like that, you want to live inside that sound for the next hour. You pull it up in Plex, hit play, and then you stare at it, because the only thing Plex will offer you is a smart playlist that matches a genre string and a year range.

That’s not a mood. That’s a filing system.

So I built MusicSeed — a local-first, open-source recommendation tool that turns a single seed track (or a handful that share a vibe) into a playlist drawn entirely from your own library, ranked by how the music actually sounds and feels. It runs on your machine, reads your Plex metadata read-only, and writes playlists back only after you confirm. No cloud. No subscription. No black box.

Why I built it

Three things have been true about me for a long time: I’m fascinated by recommendation systems, I care deeply about my music collection, and I believe open source is the most effective way to have a beneficial impact on people’s lives.

MusicSeed is where those three things meet. If it helps someone like me fall in love with their own collection again — find the gems they forgot they owned, keep a mood going, build a playlist in seconds instead of an afternoon — then I’ll know I’ve given back a small piece of what the tech community has given me over the years.

I’ve also had the privilege of some spare time lately, and with it the chance to re-encounter something I’d let slip away: the pure joy of creating software for no other reason than making something new that others might enjoy as much as I do. No roadmap, no business case — just the itch to build.

Made for collectors, not streamers

MusicSeed isn’t for passive streamers. It’s for the people who run Plex, who tag and back up and organize, who treat their library like the culture it is.

It’s for the music collector who’s passionate about enjoying — and discovering — the gems already sitting in their own collection. The deep cut from 2007 you haven’t thought about in a decade. The B-side that perfectly extends the track you’re playing right now. Collectors aren’t hoarders; they keep music discoverable for themselves, their friends, their families, and the future. MusicSeed exists to serve exactly that.

What it does, through the eyes of a collector

Every feature in MusicSeed started as a real frustration. Here’s how it answers them:

“I want to keep this exact mood going.” You just heard something and want more like it — now. Give MusicSeed that one track as a seed and it returns a full mix written straight back to Plex. Seed to playlist in seconds, not an afternoon of manual digging.

“I know I own something that sounds like this — I just can’t find it.” Smart playlists match genre and year strings. MusicSeed matches how music actually sounds, using Plex’s own 50-dimensional sonic analysis vectors for sound-based similarity. You don’t need to remember the tags; the sound does the remembering.

“Why did you pick this track?” Every recommendation is explainable. Run it with --explain and you’ll see exactly why each track ranked where it did — which signal pulled it up, and which held it back. No mysterious black box.

“I’ve heard everything I like a thousand times.” A novelty signal leans toward the tracks you’ve barely played, so the mix surfaces the gems you forgot instead of the five songs you already loop.

“One signal is never enough.” MusicSeed ranks on six signals — sonic similarity, popularity proximity, style, genre, era, and novelty — weighted and combined into a single score, and each weight is tunable. You can shape the mix toward sound, toward era, toward discovery, whatever the moment calls for.

“I don’t trust the cloud with my library.” It’s local-first. One SQLite file holds all your MusicSeed state; nothing about your library ever leaves your machine. The only network calls are optional enrichment lookups.

“Will it wreck my Plex?” No. MusicSeed reads your Plex metadata read-only and writes only playlists through the Plex API — and always after you confirm. Long jobs are resumable, dry-runs sit next to every write, and backup is literally copying one file.

Honest, local, and yours

Streaming knows everything about everyone and nothing about your library. MusicSeed fixes discovery for the people who actually own their music. It’s MIT-licensed, built in the open, and made to be tinkered with, extended, and shared.

If you run Plex and care about what’s in your library, this was made for you.

Welcome home.