Singer Mehdi Hassan, who had an international following in the millions, died June 13 in Karachi of multiple organ failure. He was 84 and had been ailing for some time.Hassan, who specialized in a South Asian form of ballad known as ghazal — he was known as “the emperor of ghazals” — recorded more than 20,000 songs in a 50-year career including such hits as “Patta patta boota boota” and “Kab ke Bichhare.” With his deep mellifluous voice full of feeling and emotion, Hassan crossed the divide between India and Pakistan, even singing once for then-Indian prime minister A.B. Vajpayee. Born in a family of musicians in a Rajasthan village in colonial India, Hassan migrated with his family to Pakistan when the sub-continent was divided. The family saw its fortunes decline in the new country, however, and as a youngster, he worked in a bicycle shop and as an auto mechanic even as his father and uncle trained him in North Indian classical music. Slowly, the youngster gravitated toward ghazals and first drew attention in 1957 when he performed on Radio Pakistan. Even though the format is stylized, Hassan broke from form and managed to put his own stamp on his compositions. He also culled from the folk music of his native Rajasthan and combined it with the ghazal. He gravitated toward films, first in Pakistan; as his following spread to neighboring India, Bollywood beckoned. From the 1960s through the ’80s Hassan sang for films such as “Ek nazar,” “Do raaste,” “Deewane do” and “Lawaaris.” But with his health failing he cut back on his performances in the 1990s, especially after his first wife died in 1998. Survivors include his second wife and 14 children.