How Frankenstein Audio works

Frankenstein Audio is a stem studio: upload songs, let the AI split them into vocals, instrumental, bass and drums, then stitch parts of different songs into one seamless mashup — every part automatically fitted in key, tempo and tuning. When it sounds right, export it as a mastered track or a YouTube-ready video.

Getting started

1. Create an account and click the verification link we email you — uploads and exports unlock once you're verified.
2. Upload a song (MP3, WAV, M4A…). Separation runs on our GPU pipeline; a few minutes later the song appears in your library with its stems, tempo map, key and beat grid analyzed.
3. Add stems to the arrangement. Every song's stems show up in the four stem groups — Vocals, Instrumentals, Bass, Drums. Press + on any stem to add it as a lane.
4. Preview. The arrangement plays exactly as the export will sound — fits, pitch, speed and transitions included.
5. Export when it's right: a mastered audio file or a 1080p video.

The library & stems

The Library (header button) lists your uploaded songs — rename or delete them there; renaming a song renames its stems everywhere. The stem groups on the main page are your building material, with search to find a stem by title, BPM or key instead of scrolling.

Stems can carry refinement variants (see below): a refined stem appears as its own selectable tile, and refinements stack — the tile label reads like a recipe (e.g. Cleanup · Remove hook · Clarity).

The arrangement studio

Lanes and the anchor

Each row is a lane holding one stem. Add as many lanes per type as you like. One lane is the anchor ⚓ — usually your instrumental — and every other lane is automatically fitted to it: keys are rotated to match, tempos stretched to the anchor's grid, tuning aligned. That's why a vocal from one record sits naturally on another record's band.

Editing

• Split & slice — cut a lane into independent slices with ✂, drag each where you want it. Dragging snaps to the bar grid; hold Alt to place freely.
• Click a waveform to audition from that spot — the played span highlights, and ✂ cut can silence exactly the highlighted span.
• Replace a slice — in a vocal lane's refine menu: pick any slice (or a highlighted span) and the app auditions your library for the verse that fits that exact spot best; use it again to re-roll the next-best pick.
• Speed — the header slider plays the whole mash slower or faster, pitch moving with it like vinyl (0.65× is full chopped-and-screwed). Preview and export match exactly.
• Per-lane pitch — a ±12 semitone slider in each lane's refine menu, baked into the render.
• Transitions — a lane can open/close with the classic DJ filter sweep.
• Drum fills — drums lanes can auto-play retrigger fills at phrase boundaries (toggle in the refine menu).

Auto-arrangement suite PRO

The premium tools do the hard arranging for you:

• Distribute verses — cuts a vocal into verses and places them across the anchor where harmony, energy and phrasing fit best. Use it when: you've dropped a full vocal on a new band and want an instant song-shaped layout.
• Fill gaps — auditions every usable slice of the vocal against each empty stretch and only places what truly fits (weak fits become quiet ad-libs, or the gap stays clean). Use it when: distribution left holes and you want them sung.
• Close gaps — the opposite: cuts the band inside each gap on invisible seams so the arrangement tightens instead of filling. Use it when: the song should get shorter, not busier.
• Echo-fill & break polish — ducked echoes of the last phrase across a gap, and tail-outs plus a drum fill into each re-entry. Use them when: a break feels empty or a re-entry feels abrupt.
• Magic fill ✨ — an empty vocals lane fills itself with the best-fitting verses from other songs' vocals; an empty band lane picks the best backing for your vocal. Re-roll by removing the lane and pressing ✨ again.
• Trim other lanes — shortens the band to your vocal's length by removing repeated sections on seamless seams.
• Re-track beats — a stronger beat-tracking model re-analyzes a song's grid and is adopted only if it measures better. Use it when: a song feels off-pocket mid-verse even though the starts line up.
• AI beat generation — generate an original beat from a text description, optionally matched to a song's BPM and key.

Stem refinements PRO

Each lane's ⋯ refine menu offers per-stem processing. Refinements render a new variant tile (your original is never touched) and stack in any order; ↩ pops the last step.

Use-cases: Rapify turns a rock or funk band into a rap-ready bed; Epicenter gives bass subwoofer weight; Remove hook mutes the chorus so a distributed vocal doesn't fight the band's own hook; Bleed cleanup rescues stems where the vocal leaks into the instruments.

Exporting audio & video

Press EXPORT under the arrangement panel:

• Audio — MP3 320 kbps, MP3 192 kbps, or lossless WAV; every render is mastered to −14 LUFS streaming loudness.
• Video — 1080p H.264/AAC, YouTube-ready. Pick a background image (shown with the standard blur-fill album-art treatment) and an animation: golden wave, neon oscilloscope, frequency bars, spectrogram flow, or none.

Free accounts include 2 exports; video exports carry a small "Made with Frankenstein Audio" watermark. Pro exports are unlimited and watermark-free. A video of an arrangement you already exported doesn't cost a second export.

Plans

Tips & troubleshooting

• "Verify your email" errors — check your inbox for the link (the banner in the studio can resend it). Uploads and exports stay locked until then.
• A vocal drifts off-beat mid-song — the source song's beat grid is probably imperfect; run Re-track beats on it, then re-distribute.
• Some songs have 3 stems — not every mix has separable drums; those songs simply have no drums stem, and everything else works normally.
• Keep same-song lanes together — slices of one song's stems stay phrase-locked when they share the same cuts; the auto tools do this for you.
• Speed changes pitch on purpose — the slider is varispeed (the slowed/sped-up aesthetic). Use the per-lane pitch slider for pitch-only moves.