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

# Build Practice Apps

> Create play-along tracks by removing a specific instrument from a mix

Build practice and jam-along experiences by removing a single instrument from a song. Use the `residual` option to get everything *except* the target instrument — perfect for guitarists, bassists, drummers, or any musician who wants to play along with the rest of the band.

## Create a Task

This example removes the guitar from a track. The `residual: true` flag returns everything except the guitar — your ready-to-use backing track:

```python build_practice.py theme={null}
import requests

API_KEY = "your_api_key"
HEADERS = {"Content-Type": "application/json", "x-api-key": API_KEY}

response = requests.post(
    "https://api.audioshake.ai/tasks",
    headers=HEADERS,
    json={
        "assetId": "your_asset_id",
        "targets": [
            {"model": "guitar", "formats": ["wav"], "residual": True}
        ]
    }
)

task_id = response.json()["id"]
print(f"Task created: {task_id}")
```

```javascript buildPractice.js theme={null}
const API_KEY = "your_api_key";
const headers = { "Content-Type": "application/json", "x-api-key": API_KEY };

const createRes = await fetch("https://api.audioshake.ai/tasks", {
  method: "POST",
  headers,
  body: JSON.stringify({
    assetId: "your_asset_id",
    targets: [
      { model: "guitar", formats: ["wav"], residual: true }
    ]
  })
});

const { id: taskId } = await createRes.json();
console.log(`Task created: ${taskId}`);
```

```bash curl theme={null}
curl -X POST "https://api.audioshake.ai/tasks" \
  -H "Content-Type: application/json" \
  -H "x-api-key: $AUDIOSHAKE_API_KEY" \
  -d '{
    "assetId": "your_asset_id",
    "targets": [
      { "model": "guitar", "formats": ["wav"], "residual": true }
    ]
  }'
```

[Check Task status](https://developer.audioshake.ai/check-task-status.md) to monitor progress and download results, or use [webhooks](https://developer.audioshake.ai/api-reference/tasks/webhooks.md) to be notified when each target completes.

With `residual: true`, you get two outputs — the isolated instrument and the residual (everything else). Use the residual as the backing track.

## Try other instruments

Swap the model to create practice tracks for any instrument:

| Model | Practice scenario |
| - | - |
| `guitar` | Guitar play-along |
| `bass` | Bass play-along |
| `drums` | Drum play-along |
| `piano` | Piano / keys play-along |
| `vocals` | Vocal practice / sing-along |

## Use cases

* Build interactive practice apps for musicians
* Generate play-along tracks for music education platforms
* Create instrument-specific backing tracks at scale
* Power jam session features in music apps

> [card] [Instrument Separation](https://developer.audioshake.ai/separate-stems.md)
>
> Extract all stems from a track instead of just one.

> [card] [Build Karaoke Tracks](https://developer.audioshake.ai/create-karaoke-tracks.md)
>
> Combine instrumental + lyrics for karaoke apps.


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