India, April 29 -- A clip of elderly men transforming a routine metro ride into a lively karaoke session recently went viral but also sparked a debate on common courtesy and consideration for fellow commuters. The video of the impromptu sing-along on the Delhi Metro's Yellow Line, shared on Reddit, sees the men holding a microphone and merrily sing Pyar Hua Ikrar Hua from Raj Kapoor and Nargis's film Shree 420 (1955). Many internet users were charmed by the sight of the elderly passengers enjoying themselves. On the other hand, others raised concerns about the disruption it may have caused, as the Metro has strict guidelines on passenger behaviour and safety. "The positivity has made my day. At least it's not another video of people arguing or fighting in the metro," wrote one Reddit user. Another user argued, "Just because they're elderly doesn't mean we should allow this. You can sing, but using a microphone is crossing the line."htc...