Muriel Brunskill was born in Kendal, Westmorland, England, daughter of Edmund Capstick Brunskill. She studied singing in London and Paris with Blanche Marchesi. Her début was in 1920 at the Aeolian Hall, London. She sang at the Proms in 1921 in Elgar's "Sea Pictures", when "The Times" commented that her singing was intelligent but lacked bite, and her diction was indistinct. By 1923 Brunskill's critical reputation was much higher: "The Musical Times" said, "She is clearly one of the elect as a Bach singer."