You can't do anything automatic when it comes to programming. You need to code it one way or another.
As for the random play list.
Create an array with all the song names. You can also use a CSV and tokenate randomly; instead of random.
Then create an Event for Audio on End with your "music" tag name.
Play music file = array(int( random(0, array.width) ) w/tag "music"
or
Play music file = trim( tokenate( csv, int( random(0, tokencount(csv,",") ), "," )
w/tag "music"
with that during your game when one song ends the other will begin.
boom easy, and not automatic.
I still dont get it can you please post some screenshots? Im not that good with construct 2?