Ailing Grammy award-winning New Zealand singer Lorde has postponed her Australian tour this week after doctors advised she needed immediate rest and recuperation, her promoters said on Tuesday. Teenager Ella Yelich-O’Connor, who uses her stage name Lorde, has been touring North and South America over the past few months and played at the Coachella Valley Music and Arts Festival over the Easter weekend. She was due to kick off the seven-concert Australian leg of her world tour in Melbourne on Thursday.