> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lightloop.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Transpose Tool

> Change the key of any track, pull out an instrumental, or split it into stems — without adding anything to your library.

<Note>
  The Transpose tool is a **scratchpad**. Nothing you drop into it is added to your media library or written to your Google Drive folder — files are processed on demand, downloaded to your device, and deleted from the server a few hours later.
</Note>

The Transpose tool at [lightloop.app/transpose](https://lightloop.app/transpose) gives you the Song Editor's audio processing on its own, for any track — not just songs in your library. Use it when you need a key change or a backing track for something outside LightLoop: a rehearsal file, a track for another app, or a one-off for a guest musician.

It's the same engine behind [song transposition](/web-app/songs#transposition) and [instrumentals](/web-app/songs#instrumental-karaoke), so results match what you'd get in the editor.

Sign in with the Google account you use for LightLoop — the tool is behind your normal login.

***

## Adding audio

Two ways in:

* **Drop a file** — drag an audio file onto the page, or click to browse. MP3, M4A, WAV, AIFF, FLAC and most video files work; audio is pulled out of a video automatically.
* **Paste a YouTube link** — paste the URL and click **Fetch audio**. LightLoop downloads the video's audio track. (Nothing is added to your library — this is separate from the [YouTube import](/integrations/youtube) in the Media Library.)

Once the audio is in, LightLoop reads it and **detects the musical key**, then shows a player so you can hear the track and check that key by ear before committing to anything.

Each step reports its own progress — uploading, reading the file, detecting the key.

<Tip>
  Key detection is a best guess from the audio. If it can't make a confident call, the **From** field is flagged **set this yourself** — play the track, work out the key, and pick it manually.
</Tip>

***

## Choosing the key

Set the **From** key (pre-filled with the detected key) and the **To** key. LightLoop shows the shift in semitones and always takes the shortest path — up to six semitones in either direction.

Pitch shifting **preserves the original tempo**. The song doesn't get faster or slower, only higher or lower.

Leaving both keys the same is fine — pick an extra below and you'll still get a file out.

***

## Extras

Three options, one at a time:

| Option                        | What you get                                                                                                                                        |
| ----------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Just the transposed track** | The pitch-shifted audio on its own.                                                                                                                 |
| **Instrumental**              | The vocals removed, for a backing track. Adds a minute or two.                                                                                      |
| **Stem separation**           | The track split into its separate parts — vocals, drums, bass and the rest — as individual files, plus a mixed instrumental. Takes several minutes. |

Extras are always applied **after** the pitch shift, so stems and instrumentals come out in the key you asked for.

<Note>
  Stem separation quality depends on the model installed on your LightLoop media server. With a multi-stem model available you get four parts plus an instrumental; otherwise it falls back to a two-part split (vocals and instrumental). The **Ready** panel tells you how many parts you actually got.
</Note>

***

## Generating and downloading

Click **Generate**. Each stage reports progress — decoding, shifting, separating, encoding — and separation shows a **countdown** based on how long previous runs took on your server, so you know roughly how long to wait.

When it finishes:

* Every file is listed with its size and its own **Download** button.
* If there's more than one, a **Download all** button at the top hands you everything in a single zip.

Files stay on the server for a few hours and are then deleted automatically. **Start over** clears the session immediately.

***

## What it doesn't do

The Transpose tool is deliberately separate from your library:

* Nothing appears in your **Media Library**, and nothing is written to your **Google Drive** folder.
* It has no lyrics, timing markers or slides — for that, work in the [Song Editor](/web-app/songs), where transposition and instrumentals are attached to the song and play on your outputs.

If you want the transposed track **in LightLoop**, upload the downloaded file to your Media Library as normal, or transpose the song directly in the editor instead.