This bug was fixed in Patch 1.36.99.
- I can hear two different music singing overlays while my Sim is practicing singing or singing Karaoke
- After they stopped singing, I can still hear the singing music.
Unclear but it seems this issue is occurring mostly if you speed up your game while (or shortly before) you have your Sim sing.
- Save your game under a new name
- Restart your game (completely, not just main menu)
How to prevent
Don’t speed up your game while singing