Tier2 finds the songs fans know but radio forgot. It ranks an artist, playlist, decade, or your own taste by real listening counts, then rebuilds it from the deeper cuts. It runs entirely in your browser and talks only to Spotify and Last.fm.

First-time setup (5 minutes)

1. Get a Spotify Client ID and a Last.fm API key (steps below).
2. Click Keys at the top, paste both, and Save.
3. Click Connect Spotify and approve access.
4. Pick a tab and start building.

Get a Spotify Client ID

1. Go to developer.spotify.com/dashboard and log in with your Spotify account.
2. Click Create app. Name and description can be anything.
3. Under Redirect URI, add this exact value (including the trailing slash) and save:
4. Open the app's Settings and copy the Client ID (you do not need the client secret).
5. Open User Management and add your own Spotify account (the name and the email on your account). Apps start in development mode and only let people you add log in.

Get a Last.fm API key

1. Go to last.fm/api/account/create and log in.
2. Fill in any application name and your email. Callback URL can be left blank.
3. Submit, then copy the API key (the 32-character string). You don't need the shared secret.

The tabs

• Artist — type an artist, then choose Tiers (deep cuts below the hits), Skip-Take (skip the top X, take the next Y), or Full Discography.
• Discover — add a few seed artists and set how obscure you want it. Returns lesser-known similar artists and their strongest tracks.
• Mix — pick a decade and/or genre. Optionally rank by real play counts. Returns the tier just below the obvious hits.
• Sommelier — pick playlists as taste sources (your Cellar is always included once it exists), then Pour a Tasting for 10 deep cuts. Keep the ones you like with ✓, then Shuffle All to play them or Add to Cellar to save them. The Cellar is a private playlist that sharpens future pours. Poured songs won't repeat; "reset tasting memory" next to your taste line starts fresh.
• Enhance Playlists — pick your playlists and swap each artist's top-10 hits for deeper cuts. Toggle individual tracks in or out, then save.
• Inventory (top bar) — stage tracks from any mode, then build one compilation.

Result rows

▶ Play on Spotify plays one track in your Spotify app. ✓ Keep / ＋ Add chooses what your selection is — tap a removed hit's ＋ to keep it, or a cut's ✓ to drop it. The three buttons below the list all act on that selection: Shuffle All shuffles and queues the whole set on your computer with no playlist, Save to Spotify makes a playlist, and Add to Inventory stages them for a compilation.

Playback

Play needs Spotify Premium and the Spotify app open on the same device — the desktop app on a computer, or the Spotify app on your phone — plus a one-time Keys → Reconnect Spotify to grant playback permission. On a phone, if the app isn't already active, Play opens the track in Spotify instead. Shuffle All queues your kept songs onto that device.

Filters (top of the app)

Exclude live, remaster, holiday, instrumental, and interlude tracks, and set a release-year range. Filters apply to every result and to playback matching.

Troubleshooting

• Last.fm 403 / invalid key — the key in Keys is wrong. Re-copy the 32-character API key (not the secret), Save, and re-run.
• Spotify login fails or "user not registered" — add your account email under your Spotify app's User Management, then Connect again.
• "Invalid redirect URI" — the Redirect URI in your Spotify app must match this app's address exactly, including https and the trailing slash.
• "Spotify rate limit — wait ~N s" — too many requests. Wait the seconds shown. Heavy runs like Full Discography are the usual cause; it clears on its own.
• Play shows "Playing…" then nothing — you need Premium, the desktop app open as the active device, and Keys → Reconnect. Play any song in the app first so it becomes the active device.
• Playlists don't appear in Enhance or Sommelier — make sure you're connected. Only your own playlists are readable through the API.
• Some tracks don't match on Spotify — a few Last.fm track names don't map cleanly. Try a broader tag or a different seed.
• A change isn't showing up — check the build version next to the Tier2 logo, then hard-refresh the page.

Privacy

Your keys live only in this browser's localStorage and are sent only to Spotify and Last.fm. New playlists are private by default; "Make playlist public" is an explicit opt-in.