What about inviting the downstairs person up, turning on some music or the TV so they can see what the normal noise level is like and then going down to their unit and see what you can hear? 

I have an idea of which neighbor might have complained but we have gone the extra mile to make sure there is privacy and that guests are quiet and do not play loud music or party.

For me, it's so i don't have to work and have time to spend time with my daughter, and to be able to afford to let her do whatever she wants to do (e.g. learn sports/musical instruments/arts should she desire to do so). 

My former firms wants all their kids to be Doctors regardless their real drive. can't be that artist or music teacher. 

As far as REI goes, I've only met a couple of shady investors over the phone while I've been marketing....So anyway, I found this pretty sweet place called the Music Cafe...

One fun fact about me is that I can play 5 different musical instruments!

But my issue is they play very loud music, mostly during the day and evenings, which is during social hours, but they play the music so loud that it is impossible for anyone in my backyard to have a conversation with the person sitting next to you. 

Now there are different people coming and going all the time, nobody says "Hi", loud music late at night, pot smoke smells drifting into our yard, random people sitting in their car in front of our house running their engines for hours while they talk on the phone, permanent dumpster on a residential street etc.

Outside building looks great, that picture that I put in is the back of the building.I went at Saturday night to check on neighborhood, pub next door had loud music, train pass across the street of the building as well :)

And remotely play annoying music all day/night out of their control or something to suggest they leave...?