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 — type a decade (80s, 1980s, eighties, 1985) and/or a genre, or pick one from the list. Tier2 checks your words against Last.fm's real tags, fixes small typos (rokc → rock), and if "90s shoegaze" isn't a well-used tag it combines the 90s and shoegaze tags instead. The tag it used is shown with the results. 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.
• Manage Playlists — pick one of your playlists and Analyze. Tier2 flags songs to drop (top-10 hits by default; also duplicates, songs that fail your Filters, and songs you've overplayed) and suggests songs to add (a deeper cut by the same artist for each flagged song, plus similar songs you don't have). Toggle anything, then Apply to change the playlist in place (a private backup is saved first by default) or save a separate copy. Select 2+ playlists to merge them, or delete playlists.
• Overplayed by you — Spotify doesn't share play counts. Tier2 can use Spotify's ranking of your top 50 tracks for a period (one-time Keys → Reconnect Spotify to allow it), or real play counts from Last.fm if your Spotify account scrobbles to Last.fm (enter your Last.fm username).
• Inventory (top bar) — stage tracks from any mode, then build one compilation. It's saved in this browser and survives reloads until you hit Clear all. Make a new playlist from it, or Add to Playlist to append it to one of your existing playlists (yours or collaborative ones), skipping songs that are already there.

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. Every section has Keep all / Drop all, and Keep everything / Drop everything above the action buttons flips every row at once. Long lists show the first rows and collapse the rest behind Show all; collapsed rows still count toward your selection. 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, set a release-year range, exclude specific years or ranges (1999, 2010-2016), and blacklist artists (comma-separated; Verify artists on Spotify confirms each name). Filters apply to every result on every tab and to Spotify matching. When a song has several versions on Spotify, Tier2 picks one that passes your filters (e.g. the 1994 original over a 2015 remaster). Excluded years and the blacklist are saved in this browser.

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 Manage Playlists 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.