Seeking to soundproof front door to my apartment

Hi All,
  I live in an apartment building in NY. The front door to my apartment leads out to the common hallway, which is shared by all those whom live on my floor where all can access the trash disposal, elevator, stairs, etc.

  When there are people in the hallway speaking, taking out the trash, or perhaps kids running around, the sounds easily travels into my apartment through the front door and can be quite disturbing while I'm listening to music, or watching movies. Conversely, when I listen to music, or watch films, the sound from my A/V system can be heard in the hallway coning out of my apartment and, as a result, can be a bother to others.

  I have been contemplating of having my front door soundproofed (at least to a great degree) in the attempt to block the sounds coming from the hallway into my apartment, as well as blocking sounds from my system from being heard in the hallway.

  I totally understand  that I may not have success in complete (total) sound isolation. However, I'm sure there are ways to get solid improvements. I cannot do the work myself, and would need to hire someone to get this done.

  Any and all suggestions are welcome, particularly regarding a professional(s) whom have the skills to do the job right.

Thank you
One option is a solid core door with a towel placed at the bottom to block sound. In addition to this, you could install a large rotating/swinging bar on the wall next to the top of the door and hang a thick rug to cover the door when you are home.
Don't forget to put your speakers/subwoofers on spikes to decouple from the floor. Put plywood underneath to protect the floor. Lastly, consider Saturday from Noon to 6 p.m. as "no mans land" i.e. this is the time to play music louder than normal (but never loud after 9 p.m.). this goes a long way toward neighbor relations.
My two cents.
I can recommend the Acoustic Sciences door seal as one option

I had ASC design a sound proof listening room for me and this was part of the setup, albeit installed in dual solid doors (i.e. one door opening one way and another opening the other way). It will certainly keep out sound coming in and your neighbors will only hear you if they stand outside.

Be warned however that as dweller observes none of this will help with bass transmission which will be happening through the floor, walls and even ceiling if you fully energize the room
What kind of door is it? Is it a panel door? If so those do transmit sound more than a hollow core. You might go to a home center and buy a sheet of styrofoam insulation about 2" thick and add it to the door with double sided tape or Velcro. That might help some but I would also suspect the walls are transmitting sound as well. Most apts that have common interior hallways aren't insulated so you get that transmission of sound as well.
check out a company called acoustic block, technology has dramatically improved!
The seal is the key.  Replacing with an fully weather strip outdoor type door should cut most of the sound.  Be sure to lift the threshold to get a tight seal.  Oh, for the flat panels on inside of the door type lead wall paper.  Yes, such exists.  Of course you may need to change the hinges.  I used lead wallpaper years ago in a similar condition.  It worked.
In addition to whatever you decide, end up doing, etc. with the front door, if you are confident this is where most of the unwanted noise (or desirable music!) is entering/exiting you might want to consider a barrier in front of the door. Somewhere in this thread it was mentioned that hanging a carpet would be helpful, and it would be. Something similar (or exactly) like this would also help. Point here is that it would probably be better to introduce two or three solutions.
Actually, the problem very well might be the windows. Sound travels through glass very easily. You can hear a trailer truck rumble down the street way before it gets to the house.