Ubuntu :: Finding A Folder To Autorun A Script At Login?

I remember reading something a while back that theres a folder that you can just plonk a bash script into and it will run on login but cant find anything about it now. I have found the command $update-rc.d <filename> but scripts added this way have to lsbInit compliant and i havent got a clue where to start with that I also cant just add it to the startup applications list because for some stupid reason following the kernel update a few weeks back (this used to work fine) suddenly has no effect. Heres the script incase anyone wants extra points for telling me why all of a sudden it doesnt work. (ive also made the same script run as a python3 program to no effect.)

Code:

#! /bin/bash
# This is a simple bash script to automatically play a
# random song on banshee 15 seconds after startup
sleep 15 && banshee --play