Replace a section of lyrics in an existing song to generate new music. The new lyrics should overlap with the original lyrics, and the timing should correspond appropriately.

Credits cost: 15

How to Use

Original lyrics:

[Verse 1]
Walking down the street
Feeling the beat

[Chorus]
This is my song
Singing all day long

[Verse 2]
Under the moonlight
Everything feels right

[Outro]
The night goes on

If you want to replace Verse 2 with new lyrics:

• infill_lyrics: [Verse 2]\nDancing in the rain\nForgetting all the pain (the new lyrics to replace)
• prompt: This is my song\nSinging all day long\n\n[Verse 2]\nDancing in the rain\nForgetting all the pain\n\n[Outro]\nThe night goes on (context with original lyrics before and after the new lyrics)
• infill_start_s: 45 (start time of Verse 2)
• infill_end_s: 60 (end time of Verse 2)

This way, the system can generate the best result based on the context and new lyrics fragment.

Auto Concat Feature

When auto_concat is set to true, the system will automatically concatenate the replaced sections into complete songs:

1. Replace Section: Generates 2 replaced music fragments
2. Auto Concat: Automatically concatenates each fragment into a full song
3. Result: Returns 2 sets of paired data, each containing:
   • replaced: The replaced section fragment
   • full: The complete concatenated song

Response format with auto_concat:

{
  "code": 200,
  "data": [
    {
      "replaced": { /* Fragment 1 data */ },
      "full": { /* Complete song 1 data */ }
    },
    {
      "replaced": { /* Fragment 2 data */ },
      "full": { /* Complete song 2 data */ }
    }
  ],
  "message": "success"
}

Without auto_concat (default): Returns only the 2 replaced fragments, you need to manually call the concat API to get complete songs.

Important Notes

• infill_start_s must be less than infill_end_s
• Both time values must be non-negative
• The new lyrics should have some overlap with the original lyrics
• Timing should correspond appropriately for best results
• When using auto_concat=true, polling may take longer as it waits for both replace and concat operations to complete

Polling Result

Use the task query endpoint with the returned task_id to poll for results. Recommended polling interval: 15-25 seconds.

Status codes during auto_concat:

• 202: Task in progress (replace section or concat in progress)
• 200: Task completed successfully