To brief an audio-reactive music visualizer, send four to eight stems as separate WAV files, all the same length and start point as the final master: at least a lead vocal, drums (or kick and snare split out), bass, and the main melodic element. Those are what the animation is built from. Isolated audio levels become the movement, the light and the deformation in the video. This post covers what to export and why.
Why stems, not just the master
A finished master is one blended signal. Ask software to react to it and everything moves at once, the same way, all the time. Stems let me pull the kick out from under the vocal, drive a camera push off the bass and a flicker off a hi-hat, and let the lead vocal control the one element the eye should follow. The result feels scored to the track rather than bouncing to it.
Which stems to include
- Lead vocal. Almost always the element the viewer follows. Send it dry or lightly processed, not drenched in reverb.
- Drums. Ideally kick and snare as their own files, plus a full drum bus. Percussion transients carry most of the rhythmic animation.
- Bass. Drives weight: low-frequency motion, scale, camera moves.
- Main melodic element. The synth, guitar or pad that sets the harmonic mood.
- One or two colour stems. An arp, a texture, a backing vocal, anything with a movement you want reflected.
You do not need every channel from the session. Six well-chosen stems beat thirty.
How to export them
- Format: 24-bit WAV or AIFF. Not MP3.
- Sample rate: whatever the session runs at (44.1 or 48 kHz is fine). Keep every stem the same.
- Length and start point: every stem exported from bar 1 to the exact end of the track, so they line up when stacked. This is the most common mistake.
- Levels: export at mix level, no limiting on individual stems, no master bus processing baked in. If a stem clips in solo, pull it down a couple of dB first.
- Naming: something like
Artistname_SongName_01_leadvocal.wav,Artistname_SongName_02_kick.wav, and so on. Put the BPM and the song key in the folder name if you know them.
Zip the folder and send a link (WeTransfer, Dropbox, Drive). Include the final master separately so I can check the stems sum back to it.
If you only have a flat master
That works. I separate the key elements from the master in Logic Pro before the audio-reactive work begins. Modern separation is good enough for a precise result on vocals, drums and bass.
What else to send with the stems
- Final lyrics as plain text, with any timing notes, if it is a lyric video.
- The cover art or any existing visual identity for the release.
- One or two references, visualizers, films or artworks, for the feeling rather than to copy.
- The release date.
FAQ
Do the stems need to be mixed and mastered first?
The mix should be close to final. If the mix changes a lot after I have started, the audio-reactive pass has to be redone against the new stems.
Can you work from a multitrack session file directly?
Send stems rather than a Logic or Ableton project. Bounced audio removes any dependency on plugins or sample libraries I might not have.
What if my track has no vocals?
Then the lead melodic element usually becomes the voice the animation follows. Instrumental tracks work well as visualizers.
Is there a minimum number of stems?
Four is a comfortable minimum: vocal, drums, bass, melody. More gives finer control. Fewer starts to look like it is reacting to a master.