It's been a tiring day. You're in the Metro on your way home from work. Things at office aren't going too well. But then six youngsters hop on. They are positively bursting with energy and sporting infectious smiles. That's enough to lift your spirits. But your mood gets even better when they burst into Chhaiyya chaiyya, the smash hit from Dil Se. The group performs an impromptu a capella version of the track, with two beatboxers substituting for the instruments. Their pitch-perfect rendition carries on for about three minutes and when it's done, you break into applause along with other passengers, having forgotten your worries for a while.