7. Dont Join In With A Busker
This is a bit like going to a pop concert and deciding to get up for a bit of a sing-song with the artist on stage. To a busker, the underground is their arena. Passengers are their crowd. You are not their duet partner. The last thing these stalwarts of the music industry want is some Karaoke queen to come bouncing along like Lassie coming home to ruin their musical stylings. Enjoy them, pay them but please for the love of tube station etiquette do not attempt to form a Glee group with them in the middle of the Piccadilly line. They will bite.