It turns out Sparky Danger Organ's singing voice is fine, the problem was my musically-challenged code. Fortunately @MLE_online taught me about Arduino tone(), and now Sparky sings beautifully under musically competent direction.
This particular piece was from https://github.com/robsoncouto/arduino-songs
@regorlas ha! The Boston Museum of Science plays songs on their Tesla coils (last time I went they did Taylor Swift), but I’d never thought about someone doing it on a more reasonable scale @MLE_online