Same music under every Shorts episode: Timeline soundtrack settings

Should every episode of a series share a music bed?

If you want the show to sound like one show, yes. YouTube's launch post names sequential playback as a feature of Shorts series, so a viewer may hear episode after episode in one sitting. A recurring bed makes the join feel intentional, and a different loudness each time makes it feel stitched.

YouTube's shows page also asks for high-quality sound, so set the bed once and keep it fixed.

The Timeline settings that fix a bed

Timeline 1.0 has an optional soundtrack object with a url, gain_db, loop, fade_out_seconds up to 10, and duck_db from 0 to 20. Ducking needs a real audio spine, so it cannot be used when audio.mode is silence.

Write the settings once and send the same values with every episode. The only thing that should change from render to render is the voice track and the picture slots.

Practical notes

Episodes of different lengths need the bed to cover the whole spine, so set loop to true for a short file.

Check the ending too. fade_out_seconds takes up to 10 seconds, and a short fade on every episode gives sequential playback a clean seam from one Short into the next. Avoid fades that run longer than the episode can spare, because Sume refuses a soundtrack fade longer than the spine.

Do not change the gain mid-season because one episode feels quiet. Fix that episode's voice track instead, so the bed stays a constant. If the bed itself must change for a new season, change it at the season boundary and say so in your notes. And keep a copy of the exact request body in the ledger, since the settings are the style guide.

• One music file, imported once to media.sume.com.
• One request template, filled in per episode.
• Listen to two episodes back to back before publishing the block.

Cost

The soundtrack mix costs nothing extra. Timeline bills $0.10 per output minute, rounded up, and uses worker ffmpeg with no model inference, so a ten-episode season under a minute each is ten billable minutes, $1.00, plus whatever the music file itself cost to make.