The piano trick

This classic of card magic allows the magician to make a single card change places under very mysterious and possibly musical circumstances.

A volunteer sits at a table and places their hands in front of them as if they were playing the piano. From your pack, you take two cards, and place them both between the spectator's third and little finger on the left hand saying, "Two cards, that’s one pair."

Then you place another two cards between the third and second fingers saying, "Two cards, that’s another pair." Next you put two cards between the first and second fingers saying, "Again, two cards, that’s another pair." Lastly for the left hand, you place two cards between the spectator’s forefinger and thumb saying something like, "Two more cards, another pair here as well."

Then on to the right hand. You do the same, taking two cards and slotting them in, repeating, "Two cards, another pair", for each finger slot. Move over the hand, but when you get to the final right hand thumb and forefinger, you take only one card. Pop it in stressing, "Only one card, an odd card here."

What goes in must go out. Pair by pair, starting with the left hand, you take the pairs of cards out, and separate them one into each of two piles, side by side. With each pair you say, "Here is a pair" then separate them onto the two piles.

Continue from the spectator's left hand to the right hand, pair by pair, two cards separated into two separate piles until you come to the all important remaining single card. Hand this odd, single card, to your volunteer and ask them to place it on top of either of the two piles.

Summon up all your magic acting skills. You simply tap the pile the volunteer placed the final single card on, and say that this single card will magically and invisibly move across to the other pile.

Pick up the pile to which the single card was added. Count through, separating the cards in that pile into side by side pairs saying each time you count off two, "Here’s a pair." Yippee, there are four pairs of cards so the extra card has vanished! To prove this you separate the cards in the other pile in the same manner, pair by pair, but there is a single card left over, so the odd card must have jumped unseen across to the other pile!

Well, it could be invisible transporting of a card by magical powers. But, of course, it isn't. This trick works because in reality your volunteer is holding four pairs of cards in their left hand (4 x 2 = 8) and three pairs and one odd card ((3x2) +1 = 7) in their right hand. You have fooled them with a bit of linguistic legerdemain – that’s fancy talk.

The paired cards, four from the left and three from the right are then divided into two piles, forming two identical piles containing seven cards (an odd number). But because all the way through you've been stressing, "Here’s a pair", your volunteer hasn't noticed. They assume both piles are even.

Yes, it’s another mind slip to cover the simple maths. With two piles of seven cards, adding the last single card turns that pile into an eight. So when you count them off two by two they are a full set of four even pairs.

The spectator wonders, "Where did that odd card go?" The pile where the extra single card wasn’t added is still seven so it shows three pairs and one left over. That’s the odd card that your spectator assumes (wrongly) must have flown from the other pile.

Once again, this trick shows how easy it is to be fooled by repetition. Don’t believe everything you hear!