John Farquarson Leonard was born March 1, 1881 at Fulham, London, England. On the death of his mother he was raised by two maiden aunts. He had inherited a gift for music from his father. Jack's father married a widow when Jack was six and the family reunited. Jack's father immigrated to Canada in 1899, taking his second wife, Jack and five other children. Jack and his father arrived in Vancouver ahead of the family. Dissatisfied, Captain William Valentine and Jak headed east again to Salmon Arm. The family settled in Salmon Arm, homesteading 160 acres on Foothills Road.
At the age of twenty Jack qualified as a millwright and worked in Beaver Mouth, Golden and Chase. He was the organist at the Anglican Church in Golden.
Jack relocated to Salmon Arm and joined the contracting firm of James L. Parker and Leslie Jackson. They built the Montebello Hotel and the Masonic Lodge. When the company dissolved, Jack became the Assistant Post Master. Both Jack and his father were active Masons.
During W.W. I, Jack went overseas with his brother Reg in 1916. Before leaving, he trained in Kamloops, met Isabella Carter, and, in 1916, the coupled married in Salmon Arm.
Jack farmed in Sardis, BC after the war. He then went to technical school in Vancouver where he earned his teacher's certificate. He worked at St. George's Indian Residential School, north of Lytton, Cloverdale, and Langley.
Throughout his life, Jack produced operettas and musical compositions. He died May 10, 1967.