For the Tusk Tour, the band used an Oberheim four-voice synthesizer played by keyboard tech Jeffery Sova to cover the horn parts. An OB-X with a cassette interface was kept backstage if the Four-Voice broke down. Christine McVie, who was expected to handle a percussion part for live renditions of "Tusk", instead opted to play the accordion, an instrument she never intended to learn. "It was just laying around the stage one day. I wasn't sure what I was going to play on `Tusk.' I thought I might wind up playing some kind of percussion, but I just picked it up and started doing the riff."