The 9091 kettle has a melodic whistle made of brass in a shape that has never been seen before and consists of two small vents in which the tuners that reproduce the notes mi and si are inserted. Richard Sapper created this kettle inspired by a childhood remembrance, the poetic sound of boats' sirens at the River Rhine: This is because the melody that accompanies the vapor outlet must be pleasant and not anxious like the whistle of boilers. This induction kettle is a polysensory object that will not interrupt an enjoyable break with a whistle but with a captivating melody.