Remix Lab

Remix Lab is the AI-assisted module for taking a track you love apart and stealing the bits you want. Upload any audio (or pick one from your library), let the splitter pull out drums, bass, vocals and "other" stems, then slice, warp, retempo and transcribe to your heart's content. The chops you save land in your Sample library, ready to drop into any project.

When to use Remix Lab vs the Sampler: the Sampler works on clean, single-instrument samples you already have. Remix Lab is for whole tracks — anywhere you'd otherwise be hunting for an a-cappella, a drum break, or a vocal chop.

Each remix returns four AI-separated stems:

• Drums — kicks, snares, hats, percussion. Perfect for chopping breaks.
• Bass — sub and mid-bass. Great source for retempoed sub one-shots.
• Vocals — leads, ad-libs, harmonies. The a-cappella you couldn't find.
• Other — everything else: pads, leads, guitars, FX. The chord/melody source.

Each stem card has Mute, Solo, Download, and Match BPM — type a target BPM and the stem time-stretches to fit. The stretched version is what gets used when you slice.

The sensitivity slider runs the transient detector again — low sensitivity yields longer slices; high gives many short ones, useful for hi-hats and chops. The editor caps at 64 slices to keep things manageable.

Saved slices land in your Sample library with:

• name <source> — <stem> 01 (rename anything you want first),
• tags remix:<stem> and remix-slice,
• full duration metadata so Forge knows how to warp / pitch it.

The warp lane under the waveform lets you stretch a stem non-uniformly — different parts at different rates. Use it when "Match BPM" alone leaves drift, or when you want to lock a live-recorded stem to a strict grid.

1. Click the strip to drop a marker at that source time.
2. Hit Seed to auto-place markers from detected transients (uses your project's target BPM).
3. Hit Render. A new warped preview appears below the lane.
4. Reset clears all markers and returns to the uniform stretch.

Remix Lab analyzes the "other" stem two ways:

• Chord timeline — clickable chord chips below the waveform. Click a chip to seek; hit Copy MIDI to grab the progression as a MIDI clip ready to paste into any instrument track.
• Note roll (Pro) — a piano-roll of the actual melody, transcribed note-by-note. Export MIDI bounces a full Standard MIDI File.

Toggle Chords / Notes / Both at the top of the panel. The AI Coach feeds the detected key and top notes into its suggestions, so its tips reference the actual melody.

The coach panel on the right gives you a running stream of suggestions tailored to whichever stem you're working on. Two modes:

• Pro — production-language tips: "Side-chain bass to kick, try a half-time variant on bar 17, swap chord IV for vi to add tension."
• Beginner — plain-English equivalents: "The bass and kick are stepping on each other — let the kick get out of the bass's way."

Studio-tier accounts can host a live remix session:

1. In the Remix Lab header click Start session. You get a 6-character invite code.
2. Copy Invite. Anyone on the link joins instantly (up to 4 peers).
3. Edits are CRDT-merged — two people can add slices or warp markers on the same stem at the same time and nothing stomps. Each peer's cursor and selection color is visible in the sidebar.
4. Chat lives in the same sidebar; messages persist for the session.

• Every remix counts as one project. Free plan = 3 projects/remixes total. Pro / Studio = unlimited.
• Stem split — Pro and Studio. Free tier can preview the workflow but can't run the splitter.
• Warp markers & note transcription — Pro and Studio.
• Collaborative sessions — Studio only, up to 4 peers per session.

See Getting Started → Plans for the full tier table.

Long tracks (5+ minutes) can take up to 2 minutes. If a job has been queued for over 5 minutes, refresh — the worker may have crashed and will auto-retry. Persistent failures: open a bug from the report button (the job ID is attached automatically).

The signed URL for the stem expired (1 hour TTL). Close and reopen the Stem Editor — Forge requests a fresh URL on each open.

Usually too many markers crammed into a short segment. Hit Reset and seed again, or thin out the markers by clicking the red handles. Aim for one marker per beat at most.

The "other" stem often contains layered pads + leads + FX. For best results mute everything but the melody source first (use the Stem Editor on a single instrument-isolated slice), then transcribe.