Atari Punk Sequencer
Highly suggest doing this project in this order:
1) make a solid atari punk console, one you can rely on and you know well, I have a great diagram on my APC page on this site.
2) separately build a 555 timer that triggers a reliable 8 step LED sequence
Once you have both of these operating on separate boards (using same voltage 6 or 9 volts), you should meld them together using lots of the different 8-step sequencer diagrams out there. You have to use pots and schotky diodes, there are no shortcuts on this. Every pot you add changes the tone of this system so you won’t know exactly how it sounds until you’re actually done with the whole thing.