A style of music in which an unaccompanied vocal performer attempts to imitate the sound of a synthesizer, drum machine, sequencer, or other electronic instrument. This form is most frequently practiced by people attempting to identify or discuss a song rather than performed by musicians.
Example of a practical a capelletronica performance:
Lars: "I was listening to this M83 track yesterday and when it was all like 'duh-nah-nuh-NUH,' I was all like 'wow.'"
Klaus: "Wow, what track was that?"
Lars: "I don't remember, but maybe it was more like 'bap-ba-reee-BOP!'"
Klaus: "Oh, yeah. Midnight City."