Most of the violence is played for laughs, however it sometimes gets bloody.
A man is seen beaten on the ground with bloody wounds on his face.
A man has his face crushed by a record press. He is then seen running out of a building holding his face, the trailer briefly shows his face after being crushed.
The same man then has his teeth and "voice" removed (offscreen).
A man uses a time bomb to explode a stage prop that possibly kills others around it. We only see the explosion itself.
A man is pricked in the finger with a pen and signs a contract in his own blood.
During a musical number, a trio of band members dismember fake body parts as a part of their act, and "create" a monster, another singer, who appears on stage with fake, bloody stitch wounds around his limbs.
A character is (non graphically) strangled.
A man is electrocuted, mostly played for laughs, and lights on fire. However, in the aftermath, it is depressing as we hear this man has died.
A man stabs himself, we see bright blood around the wound, and another man pulls out the knife, seemingly resuscitating the man. The wounded man then briefly stabs the other man in the chest (no blood) thought it doesn't seem to harm him.