How do I reuse one theme track across every Shorts episode?

Make the theme once as a durable audio file, then stitch it with each episode's dialogue through Timeline audio's concat. Both audio detach and Timeline audio cost $0.01 per job in Sume prices.

The join is sample-domain with no re-synthesis, so the theme plays the same way in every episode.

The two audio jobs

POST /v1/audio-detach extracts the audio track of one Sume-hosted video into a wav, leaving the video untouched. POST /v1/timeline-1.0/audio with operation: concat joins 1 to 20 ordered parts, each { url, source_in?, duration? }, into one gapless file. Both are polled through the job envelope.

Detach once, then split with Timeline audio when you need many ranges; the docs say so directly.

A season layout

Per episode: theme sting, dialogue, theme tail. That is three parts, one concat, and the output goes into the audio.url of the episode's Timeline render. Ten episodes is ten concat jobs, which is $0.10.

If an episode comes from a generated clip with native audio, detach that audio first, as in the 180-second post. Read the Timeline audio page for the exact fields.

• Keep the theme as its own file with a stable URL.
• Write each episode's parts[] in a template.
• Do not mix sample rates by hand; let the join handle it.

Mixing the theme under dialogue

Concat joins audio end to end. It does not mix one track under another. If you want the theme under dialogue, do the mix in the Timeline render, where the audio spine is part of the edit, and keep concat for the sting and tail that go before and after.

A clean layout is: render a 5-second sting once, concat sting plus dialogue plus tail per episode, and hand the result to the Timeline render as the audio. Because each concat is a $0.01 job, even a 100-episode season costs $1.00 for this step.

Check lengths before you join. A parts[] entry with a source_in and a duration lets you take a slice of the theme instead of the whole file, so the same theme file can serve a 15-second and a 60-second episode.

Naming the audio files

Give each file a name that says what it is: theme-sting-5s, theme-tail-8s, ep03-dialogue. When a concat job fails, the part list is the first place you look, and names make it readable.

Keep the output URLs in the same table as the episode masters, so a re-render of one episode can reuse the same audio without a new join.

A last check on rights: music you generate or license for the theme should be cleared for use on every platform you plan to post to. Record the source of the theme file next to its URL, so a claim months later is a lookup.