they clash and rejoice

People amaze me, I look at them and they are all so very different, and we make connections, certain people mean something to certain people.
Connect, that's what they do, they join up in some sort of harmony.
Similar to the notes you hit on the piano or guitar, they fit together like lock and key and become a mechanism of their own.
Just like the notes that ring true, there are notes that do not agree, with that comes people that do not agree.
Clashing like a semi-tone chord, they argue and complain while with one another.
Rejoicing like a perfect fourth, they smile and love one another.