I am at a birthday party. Everyone is jolly. At some point a woman gets up, grabs her violin, and starts playing a merry Irish tune. A few seconds later, another woman, who is sitting not far from me at the laden table, picks up the rhythm with her foot: whoop, whoop, whoop… I am transfixed in no time. A few hours later, I am still at a loss: was it the violin or the foot that did the trick. I cannot be sure, but I am definitely leaning toward the foot.