Google trick turns mobiles into carol karaoke machines Deck the halls with...er, line? Turn your mobile into a Christmas carol karaoke machine with a hidden Google trick. GOOGLE has flung itself fully into the festive spirit with a hidden trick that will turn your mobile into a Christmas carol karaoke machine. If you struggle to remember the words to 'We Wish You a Merry Christmas' it's high time you got some help. And it has arrived. All you need to do is type: "Let's go carolling" into Google on your phone and you'll be met by five famous carols. Tap a song and sing along. One of five carols found on the hidden Google trick. Just tap on the one you fancy singing, be it 'Jingle Bells' or 'Deck the Halls', and it'll turn your phone into a karaoke-style screen that plays the triumphant tune along with lyrics and bouncy ball to follow. With only five carols, it's a little treat to warm up the vocal cords, but if you want to go all-out Mariah, there are plenty of other decent karaoke apps. We recommend checking out the free karaoke app Lucky Voice. Otherwise, if you're in need of an impromptu bit of Christmas cheer fire up this hidden trick and break out the egg nog. Oh, that's what they are singing! The free Lucky Voice app is another good karaoke option for Christmas.