Answer:
I am owned by every man though my length differs. Their wives uses me after getting married.
I plow and plow but never sow.
Before I grow I'm small. When I'm old I grow tall. When I die I give a mighty fall.
You can see me in water, but I never get wet. What am I?
I can be written, I can be spoken, I can be exposed, I can be broken. What am I?
I am a rock group with four members. All dead one was assassinated.