Electrical gremlin

So this morning 'm heading off to work and noticed my airbag indicator light on in the dash. (No accidents), also no rear speaker sound. Then on the way home, I tried the horn as someone pulled right in front of me, and I had no horn. All should not be on the same circuit should it ? I'll check for fuses tomorrow, but find it hard to believe that all 3 issues came at once. Ok maybe the horn, as I don't remember the last I used it. Any recommendations out there for troubleshooting ?