After replacing the the dead light bulb that illuminates the speedometer, I reconnected the battery and found that the headlight high beam, the blue high beam indicator light and the horn stopped working. The new speedo bulb did not work as well.
All of the turn signal lights still work as do the oil, start, and turn indicator lights.
The bike came to me without a working low beam. Only the high beam worked.
Since the horn button and high beam switches are both housed in the left handlebar assembly and perhaps share the same wiring, the problem might be localized there.
I will now go research how to use a multimeter.