Format
MP4 (H.264) is the safe choice. WebM and MOV also load, as do PNG, JPG
and WebP stills. Anything else is rejected by the file picker.
Size
Match the shape you are exporting: 1080 x 1920 for 9:16, 1920 x 1080
for 16:9. The plate is scaled to cover the frame and centre-cropped, so a
clip in the wrong shape loses its edges — keep anything that matters near the middle.
The three built-in plates run 1280x720 to 1920x1080, 24fps,
1–5 MB. That is a good target; there is nothing to gain from a 4K file.
Make it loop
Playback loops for as long as your piece runs, and the seam is not hidden. Use a
clip whose last frame flows back into its first — the built-ins are 8–10 seconds.
A slow drift or a shot with no clear start reads as seamless even when it is not.
Keep it dark and slow
The notes and the strike light are the subject. A bright or busy plate flattens the
glow and pulls the eye off the keyboard. Look for deep, low-contrast footage with
gentle movement — drifting water, cloud, starfield, smoke. Cuts, flashes and fast
pans fight the camera move that is already there.
Sound is ignored
The clip is always muted. Only your MIDI and any recording you load are heard, so
there is no need to strip the audio track first.
Where it shows
In Front view it fills the whole frame behind the keyboard. In Cinematic
it is the sky above the horizon, and the floor picks up its colour, so the plate sets
the light for the entire scene.