Low beams and speakers stopped working

[LittleEcker]

As I was driving home yesterday night my low beams went out. However, the high beams still come on, but only the two on the inside come on. I can't tell if it is a connection or a bulb, or both, but the left head light prior to this had been coming on and off, possibly due to a bad connection.

In addition to this, my radio amplifier will still come on, but no sound comes through the speakers. I used to have this problem as well, but it was because the fuse would get loose and come out. But I pushed all the fuses into their place and that didn't fix anything. I'm not an expert with electronics, and any help would be nice.

Thanks!
-Ecker

[LittleEcker]

Update:

So now the left bulb will come on (most likely a bad connection), AND when the high beams come on, all four are on. The right one is perfectly connected and the bulb is fine, but it won't come on. I know this can be a common problem, but I'm curious if there's anything that would make it only one bulb, or related to the stereo, which I am still utterly clueless about.

[StereoInstaller1]

Lights and steroe have basically no relation at all, except that the same battery and alternator run both.