For more info and ordering:
http://www.buyanalogman.com/EH_Voice_Box_harmony_machine_and_vocoder_p/ehvoicebox.htm
Thjs is not very good, sorry! I don't know the chords to Mr Roboto. You don't need to sing in key in vocoder mode, just talking will almost work.
This is the Vocoder setting with distorted guitar, Floyd.