Easy to build singing arc. Use any flyback driver running at high frequency and a 1 watt amplifier and transistor to switch the DC input and the rate of the music. Here we have 12 volts at 4 amps, so the arc is inly 1/2 inch or 1 cm. The music isn't too loud, but is clear with no power supply or HV flyback noise.
The music is the Beach Boys because I'm old and like the West coast sound rather than the Mersey sound of the 60s... Even if I am English.