Of the three, the last one, “Sacred Thread,” featuring the guitarist Julian Lage and the tabla icon Zakir Hussain, packs the wiliest punch.

Other tests include patting an Indian man on the back to see whether he is wearing a “sacred thread” worn by some Brahmins, the highest-ranked caste.

He had taken his shirt off to bathe, and I could see draped over his left shoulder the sacred thread given to Brahman boys when they come of age.

In one piece, a naked man bound by barbed wire sports a defiant smile - a sacred thread strung across his torso is the only indication that he is a Kashmiri Hindu.

No one in my family seemed to know about this, though it should not have been a surprise: we had all heard the stories of how our beautiful, dark-eyed, Calcutta-born great-great-grandmother, Sophia Pattle, with whom the painter Sir Edward Burne-Jones had fallen in love, used to speak Bengali with her sisters and was painted by Frederick Watts with a rakhi - a Hindu sacred thread - tied around her wrist.