> ## Documentation Index
> Fetch the complete documentation index at: https://docs.wav.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Sing Over Instrumental
> This endpoint allows users to sing over an instrumental audio track using a text prompt and lyrics. It supports either a file upload or a URL to the input audio and generates a vocal overlay based on the provided lyrics and style.
Generate a sung vocal performance over an instrumental audio track using a style prompt and lyrics.
***
## Endpoint
```http theme={null}
POST /v1/sing_over_instrumental
```
This endpoint enables you to overlay vocals onto an instrumental audio using a textual description of the singing style and provided lyrics. Input can be either a file upload or a URL.
***
## Request Parameters
| Parameter | Type | Required | Description | |
| ---------------------- | ------------ | -------- | ----------------------------------------------------------------------------- | ---------------------------------------------------------- |
| `title` | `String` | Optional | Title of the generated music | |
| `audio_file` | `UploadFile` | Optional | Upload the instrumental audio file. Required if `audio_url` is not provided. | |
| `audio_url` | `String` | Optional | URL to the audio file. | |
| `prompt` | `String` | Required | Text describing the desired singing style. Example: "Sing in soft jazz style" | |
| `lyrics` | `String` | Required | The lyrics to be sung over the instrumental. Max 2000 characters. | |
| `gender` | `String` | Optional | Voice style. Options: `male`, `female`, `neutral`. | |
| `generate_album_cover` | Boolean | Optional | false | If `true`, generate an album cover for the generated audio |
| `lyrics_timestamps` | Boolean | Optional | false | If true, generates lyric timestamps for the output track |
| `webhook_url` | `String` | Optional | Callback URL to receive processing results. | |
> **Note:** Either audio\_file or audio\_url must be provided.
> **content-type:** multipart/form-data
***
## Sample Output
Listen to a real output:
Prompt: sing over instrumental in classical slow vibe - audio input : Moana How Far We will Go.
Download Audio
***
## Try it Yourself
Use the [Sing Over Insturmental Endpoint Explorer](/api-documentation/endpoint/sing_over_instrumental) to test this endpoint live with your own inputs.
***
## Webhook Delivery
Once the generation is complete, **webhooks** will be triggered to deliver the following:
#### Standard Requests (non-instrumental):
* 2 (webhooks) x Sing Over conversion details (one per version)
* 2 (webhooks) x Lyrics with timestamp data
* 1 Album Cover Image
> Webhook responses include detailed metadata including task\_id, conversion\_id, audio files (conversion\_path), lyrics etc.
***
## Sample Request
### cURL
```bash theme={null}
curl -X POST "https://api.wav.com/api/public/v1/sing_over_instrumental" \
-H "accept: application/json" \
-H "Authorization: " \
-F "audio_url=https://youtube.com/audio.mp3" \
-F "prompt=Sing like Adele in a soulful tone" \
-F "lyrics=Never mind I'll find someone like you..." \
-F "gender=female" \
-F "webhook_url=https://yourdomain.com/webhook"
```
### Python
```python theme={null}
import requests
url = "https://api.wav.com/api/public/v1/sing_over_instrumental"
headers = {"Authorization": ""}
data = {
"prompt": "Sing emotional vocals over a soft piano instrumental",
"lyrics": "Never mind I'll find someone like you...",
"gender": "female",
"webhook_url": "https://yourdomain.com/webhook"
}
# Option 1: Use audio_url
data["audio_url"] = "https://youtube.com/audio.mp3"
response = requests.post(url, headers=headers, data=data)
# Option 2: File upload
# with open("audio.mp3", "rb") as f:
# files = {"audio_file": f}
# response = requests.post(url, headers=headers, data=data, files=files)
# print(response.json())
```
***
## Sample Response
### Success (200 OK)
```json theme={null}
{
"success": true,
"message": "Sing Over Instrumental request submitted successfully",
"task_id": "653c5108-c827-4568-9671-9259fd6b44cc",
"conversion_id_1": "1d712957-00d9-493a-a6aa-8497ccaea9bc",
"conversion_id_2": "7d6fa7a2-292c-4a95-8bda-df8ccce44bef",
"is_flagged": false,
"reason": "",
"eta": 258,
"status": "IN_QUEUE",
"credit_estimate": 0.1,
"error_message": "",
"error_message_detail": "",
"missing_input_fields": "",
"predicted_user_intent": ""
}
```
***
## Webhook Sample Payload
Sing Over Instrumental Webhook
```json theme={null}
{
"success": true,
"conversion_type": "Sing Over Instrumental",
"task_id": "c287cca4-c03a-5074-b16a-b8da9d6a124c",
"conversion_id": "8725079f-bf68-5098-a6c8-6dcba44dcaa2",
"conversion_path": "https://cdn1.wav.com/conversions/api/standard/8725079f-bf68-5098-a6c8-6dcba44dcaa2/8725079f-bf68-5098-a6c8-6dcba44dcaa2.mp3",
"conversion_path_wav": "https://cdn1.wav.com/conversions/api/hq/8725079f-bf68-5098-a6c8-6dcba44dcaa2/8725079f-bf68-5098-a6c8-6dcba44dcaa2.wav",
"conversion_duration": 155.95,
"is_flagged": false,
"reason": "",
"lyrics": "[Verse]\nTurn up the sound\nLet the rhythm take control\nFeel every beat\nMoving through my soul\nLights are shining bright\nAnd we lose track of time\n\n[Chorus]\nMusic in the air\nDancing through the night\nEvery beat we share\nMakes everything feel right\nTurn it up again\nLet the whole world sing",
"lyrics_timestamped": "[{\"start\": 9880, \"end\": 35120, \"text\": \"[Verse]\", \"index\": 0}, {\"start\": 9880, \"end\": 10720, \"text\": \"Turn up the sound\", \"index\": 1}, {\"start\": 13720, \"end\": 15600, \"text\": \"Let the rhythm take control\", \"index\": 2}, {\"start\": 19200, \"end\": 20400, \"text\": \"Feel every beat\", \"index\": 3}, {\"start\": 23480, \"end\": 25400, \"text\": \"Moving through my soul\", \"index\": 4}, {\"start\": 29520, \"end\": 31440, \"text\": \"Lights are shining bright\", \"index\": 5}, {\"start\": 33320, \"end\": 35120, \"text\": \"And we lose track of time\", \"index\": 6}, {\"start\": 39640, \"end\": 54320, \"text\": \"[Chorus]\", \"index\": 7}, {\"start\": 39640, \"end\": 40120, \"text\": \"Music in the air\", \"index\": 8}, {\"start\": 41800, \"end\": 42560, \"text\": \"Dancing through the night\", \"index\": 9}, {\"start\": 44320, \"end\": 45280, \"text\": \"Every beat we share\", \"index\": 10}, {\"start\": 45600, \"end\": 47440, \"text\": \"Makes everything feel right\", \"index\": 11}, {\"start\": 49240, \"end\": 49920, \"text\": \"Turn it up again\", \"index\": 12}, {\"start\": 51720, \"end\": 54320, \"text\": \"Let the whole world sing\", \"index\": 13}]",
"title": "Rhythm Take Control",
"subtype": "remix"
}
```
Album Cover Webhook
```json theme={null}
{
"success": true,
"conversion_type": "Sing Over Instrumental",
"task_id": "5254c422-0fab-53f0-b5e3-36abb69dd111",
"image_paths": [
"https://cdn1.wav.com/img-gen-pipeline/api/5254c422-0fab-53f0-b5e3-36abb69dd111.jpg"
],
"thumbnail_paths": [
"https://cdn1.wav.com/img-gen-pipeline/api/5254c422-0fab-53f0-b5e3-36abb69dd111_thumb.jpg"
],
"image_path": "https://cdn1.wav.com/img-gen-pipeline/api/5254c422-0fab-53f0-b5e3-36abb69dd111.jpg",
"thumbnail_path": "https://cdn1.wav.com/img-gen-pipeline/api/5254c422-0fab-53f0-b5e3-36abb69dd111_thumb.jpg",
"conversion_id_1": "eba76eae-9c77-5b09-9f2b-96a8bdef0f36",
"conversion_id_2": "1cf119ce-a78c-500b-ad43-4b1f598507cb",
"album_cover_generator_output": true,
"subtype": "album_cover_generation",
}
```
Lyrics Timestamp Webhook
```json theme={null}
{
"success": true,
"conversion_type": "Sing Over Instrumental",
"task_id": "c287cca4-c03a-5074-b16a-b8da9d6a124c",
"conversion_id": "8725079f-bf68-5098-a6c8-6dcba44dcaa2",
"subtype": "lyrics_timestamped",
"lyrics_timestamped": "[{\"start\": 9880, \"end\": 35120, \"text\": \"[Verse]\", \"index\": 0}, {\"start\": 9880, \"end\": 10720, \"text\": \"Turn up the sound\", \"index\": 1}, {\"start\": 13720, \"end\": 15600, \"text\": \"Let the rhythm take control\", \"index\": 2}, {\"start\": 19200, \"end\": 20400, \"text\": \"Feel every beat\", \"index\": 3}, {\"start\": 23480, \"end\": 25400, \"text\": \"Moving through my soul\", \"index\": 4}, {\"start\": 29520, \"end\": 31440, \"text\": \"Lights are shining bright\", \"index\": 5}, {\"start\": 33320, \"end\": 35120, \"text\": \"And we lose track of time\", \"index\": 6}, {\"start\": 39640, \"end\": 54320, \"text\": \"[Chorus]\", \"index\": 7}, {\"start\": 39640, \"end\": 40120, \"text\": \"Music in the air\", \"index\": 8}, {\"start\": 41800, \"end\": 42560, \"text\": \"Dancing through the night\", \"index\": 9}, {\"start\": 44320, \"end\": 45280, \"text\": \"Every beat we share\", \"index\": 10}, {\"start\": 45600, \"end\": 47440, \"text\": \"Makes everything feel right\", \"index\": 11}, {\"start\": 49240, \"end\": 49920, \"text\": \"Turn it up again\", \"index\": 12}, {\"start\": 51720, \"end\": 54320, \"text\": \"Let the whole world sing\", \"index\": 13}]"
}
```
***
## Common Errors
* **422 Unprocessable Entity**: Missing required fields like `prompt` or `lyrics`, or no audio input provided.
* **500 Internal Server Error**: Unexpected error during processing.
***
## OpenAPI
````yaml POST /v1/sing_over_instrumental
openapi: 3.1.0
info:
title: WAV API
version: 1.0.0
description: API for retrieving conversion details by ID.
servers:
- url: https://api.wav.com/api/public
description: Production server
security: []
paths:
/v1/sing_over_instrumental:
post:
summary: Sing Over Instrumental Using Prompt and Lyrics
description: >-
This endpoint allows users to sing over an instrumental audio track
using a text prompt and lyrics. It supports either a file upload or a
URL to the input audio and generates a vocal overlay based on the
provided lyrics and style.
requestBody:
required: true
content:
multipart/form-data:
schema:
type: object
properties:
audio_file:
type: string
format: binary
description: Uploaded instrumental audio file.
audio_url:
type: string
description: 'Input audio URL (supported format: YouTube URL).'
example: https://bucket.s3.amazonaws.com/audio.mp3
prompt:
type: string
description: Description of the singing style, tone, or genre.
example: Sing emotional vocals over a soft piano instrumental.
lyrics:
type: string
description: The lyrics to be sung over the instrumental.
example: Never mind I'll find someone like you...
maxLength: 2000
gender:
type: string
description: Voice gender to guide generation.
enum:
- male
- female
- neutral
example: female
title:
type: string
description: Title of the generated music track
generate_album_cover:
type: boolean
description: Whether to generate an album cover for the generated audio
default: false
lyrics_timestamps:
type: boolean
description: Whether to generate timestamps for the lyrics
default: false
webhook_url:
type: string
description: >-
Callback URL to receive status updates or final audio
result.
example: https://yourdomain.com/webhook
required:
- prompt
- lyrics
anyOf:
- required:
- audio_url
- required:
- audio_file
responses:
'200':
description: Successfully initiated Sing Over Instrumental task
content:
application/json:
schema:
type: object
properties:
success:
type: boolean
message:
type: string
task_id:
type: string
conversion_id_1:
type: string
conversion_id_2:
type: string
is_flagged:
type: boolean
reason:
type: string
eta:
type: integer
description: Estimated processing time in seconds
status:
type: string
credit_estimate:
type: number
format: float
error_message:
type: string
error_message_detail:
type: string
missing_input_fields:
type: string
predicted_user_intent:
type: string
example:
success: true
message: Sing Over Instrumental request submitted successfully
task_id: 653c5108-c827-4568-9671-9259fd6b44cc
conversion_id_1: 1d712957-00d9-493a-a6aa-8497ccaea9bc
conversion_id_2: 7d6fa7a2-292c-4a95-8bda-df8ccce44bef
is_flagged: false
reason: ''
eta: 258
status: IN_QUEUE
credit_estimate: 0.1
error_message: ''
error_message_detail: ''
missing_input_fields: ''
predicted_user_intent: ''
'422':
description: Validation Error
content:
application/json:
schema:
type: object
properties:
success:
type: boolean
example: false
message:
type: string
example: >-
Either audio_file or audio_url must be provided, along
with prompt and lyrics.
'500':
description: Server Error
content:
application/json:
schema:
type: object
properties:
success:
type: boolean
example: false
message:
type: string
example: Internal Server Error
security:
- ApiKeyAuth: []
x-codeSamples:
- lang: Python
source: >-
import requests
url = "https://api.wav.com/api/public/v1/sing_over_instrumental"
headers = {"Authorization": ""}
data = {
"prompt": "Sing emotional vocals over a soft piano instrumental.",
"lyrics": "Never mind I'll find someone like you...",
"gender": "female",
"title": "My Generated Track",
"webhook_url": "https://yourdomain.com/webhook"
}
# Option 1: Use audio_url
data["audio_url"] = ""
response = requests.post(url, headers=headers, data=data)
# Option 2: Upload file
# with open("audio.mp3", "rb") as f:
# files = {"audio_file": f}
# response = requests.post(url, headers=headers, data=data,
files=files)
print(response.json())
components:
securitySchemes:
ApiKeyAuth:
type: apiKey
in: header
name: Authorization
````