Karlheinz Stockhausen's fascination for the signs of the zodiac began in 1974, with the piece Musik im Bauch. The composer said that before then, he had only a vague idea about astrological signs. "While inventing a melody for each of them, I thought about the character of children, friends and acquaintances born under the different signs and studied in depth these different human types." That same year, he started composing Tierkreis, one of the most representative examples of his sound universe. Stockhausen worked for two years on the "twelve melodies" illustrating the astrological signs, before producing versions for voice and instrument, chamber orchestra and trio.