I had a squeeze horn back in 1981 when I was living in Boston and working in Cambridge, MA. Remember those? Mine had three horns pointing forward, and it made a dissonant chord. Twice it saved my butt, and they were amusing. Once, a car driver tried to right-hook me, and I honked, and he stopped, and I proceeded. When he saw I was "only" on a bike, he honked back. The other time, two pedestrians stepped off the curb against the light. I honked, and in unison, they JUMPED BACKWARDS back onto the curb!

The horn looks silly and childish, but it works. The trouble is, you can't find a well made one any more.