Luke Jerram creates spectacular art installations all over the world. He reached millions of people with his work Play Me, I’m Yours, inviting anyone to make music on the 2,000 pianos he had placed on the streets of more than 70 cities. He has also created large sculptures of the moon, the planet Mars and the sun, which were suspended in spaces like cathedrals so that visitors could admire the celestial bodies up close. Julian May follows the creation of the Jerram's latest work, made for Bradford, this year’s UK City of Culture. A Good Yarn plays on the double meaning of the word “yarn” – both a length of thread and a story. It looks like a giant multi-coloured ball of wool, three metres high, which will be rolled through the city’s streets. Luke Jerram collaborates with Bradford residents to create a kilometre-long rope, made from woollen fabric donated by the public or from second-hand shops. This episode of The Documentary, comes to you from In the Studio, exploring the processes of the world’s most creative people.