ELTON JOHN had just finished a stint in rehab. Without the fog induced by drink and drugs, he found he was able to look at the world with “clear eyes”. So when David Fahey, a gallerist, showed him work by three fashion photographers—Horst P. Horst, Irving Penn and Herb Ritts—the musician was transfixed. It marked the start of what would become one of the world’s largest private photography collections. More than 30 years later, Sir Elton has amassed more than 7,000 images.