Older guy warning...
Septum, I have watches many students get everything possible pierced. If there is a chance that the labret will effect your singing why risk that. Also labrets sometimes cause teeth/gum issues.
As a personal note the labret feels odd, it breaks the symmetry of the face and is a touch off putting and two balanced I just don't like the look of. No offence to anyone, I just think it takes a special person to pull off that look not everyone can.