The English folk singer known for most of his life as Louis Killen was a bawdy, bearded pioneer of the 1950s British folk revival, a member of the Clancy Brothers and a soloist admired for giving voice to forgotten miners and sailors in traditional ballads.

In 2010, when he was 76, Mr. Killen surprised his fans and many of his friends by resolving to give voice to another sort of lost life. He began living openly as a woman, performing in women’s clothing and a wig. In 2012, he underwent a sex-change operation.

Adopting the name Louisa Jo Killen, she continued to perform for almost two years, by most accounts winning over most of Louis Killen’s fans and all of his friends. She died at 79 on Aug. 9 at her home in Gateshead, England, from a recurrence of a cancer diagnosed six years ago, the singer’s former wife, Margaret Osika, said.

As Louis, Ms. Killen had been among the most influential voices of England’s postwar folk music scene, as both a collector and performer of 19th-century ballads and folk songs chronicling the working lives of seamen, coal miners, mill workers and laborers. Folk archivists still consider the dozen recordings made by Louis Killen in the late 1950s and early ’60s for the British folk label Topic Records to be the definitive versions of traditional English songs like “Black Leg Miners,” “Pleasant and Delightful,” “The Flying Cloud” and “The Ship in Distress.”