> ## Documentation Index
> Fetch the complete documentation index at: https://www.tella.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Add background music to your video
> Add background music to a Tella video from the built-in library or upload your own track. Background music is mixed under your existing audio and fades in and out — it does not replace your voiceover. How to upload audio, why uploaded music fades in and out, can I add a separate voiceover track.
You can add background music to your Tella video from Tella's built-in music library, or upload your own track. You can also preview tracks, adjust the volume, and remove or replace music at any time.
Audio you add here is **background music** — it's mixed in *underneath* the audio that's already in your video (your voiceover, screen audio, and so on) and plays quietly behind it. It is **not** a voiceover or main audio track, and it does not replace your existing audio.
Tella doesn't support importing a standalone voiceover or narration track, or recording a voiceover over an existing clip. To narrate a recording, record your mic at the same time as your screen, or re-record the clip. See [Can I combine two separate recordings into one video?](/docs/help/faq/combine-separate-recordings).
Background music applies to the **whole video**, not to a single clip — there's one background track for the video, and it plays across every clip.
### Open the audio tab
1. Open your video in the Tella editor.
2. Select the **audio** tab in the sidebar.
### Browse and add a track from the music library
The audio tab shows a few suggested tracks — click the play button on a track to preview it, and click **Add** to apply it.
To see the full library:
1. In the audio tab, click **Browse all**. This opens the **Music library** panel.
2. Browse **Tella music** presets organized by category — **Calm**, **Energetic**, **Focused**, and **Playful** — or use the search box to find a specific track.
3. Click the play button on a track to preview it.
4. When you find one you like, click the track to add it to your video.
The track is added across the full duration of your video.
### Upload your own background music
1. In the **Music library** panel, click **Upload** in the **Personal** section, or drag an audio file into it.
2. Choose an audio file from your computer.
3. The upload is saved to your **Personal** library, but it isn't applied to your video yet.
4. Click the track in the **Personal** library to add it to your video.
The track is now saved to your Personal library so you can reuse it in future videos, and it's applied to the current video's background music.
This is useful if you have branded music, something you created yourself, or a custom track. To share a track with your workspace, upload it to the workspace section instead — tracks there are available to all workspace members.
### Adjust the music volume
1. Use the volume control in the audio tab to make the music louder or quieter.
### Remove or replace the track
1. To remove the current track, select the remove option in the audio tab.
2. To swap it for a different track, click **Change music** — this opens the **Music library** panel where you can pick another track or upload your own.
### Why does my uploaded audio fade in/out?
Background music is meant to sit gently behind your voice, so Tella shapes it automatically:
* **It fades in at the start and fades out at the end** of your video, so the music eases in and out instead of cutting abruptly. This is expected behavior for background music — it's not a glitch with your file.
* **It's mixed under your existing audio** at the music volume you set, so your voiceover and screen audio stay in front.
If you uploaded a track expecting it to play at full volume as the main audio, that's why it sounds quiet and fades — the Audio tab is for background music, not for a primary voiceover track.
### How Tella handles track length
* If your background track is longer than your video, Tella fades it out at the end of the video.
* If your background track is shorter than your video, Tella loops it so you have music for the full duration.
### Preview your video with music
1. Click **Play** to preview the video with your background music.
2. If needed, adjust the volume until it sounds right.
### Set background music via the API or MCP
Background music can also be set and removed programmatically. Use `PUT /v1/videos/{id}/background-music` and `DELETE /v1/videos/{id}/background-music` in the [Public API](/docs/introduction), or the `set_background_music` and `remove_background_music` tools in the [MCP server](/docs/mcp-server#background-music).