Mitchell had a violin concerto written for her by Piers Hellawell - Quadruple Elegy in The Time of Freedom, which she premiered with the Ulster Orchestra and gave the London premiere at the Queen Elizabeth Hall in 1992 with the City of London Orchestra. She received an Arts Council England Award to commission and premiere a unique 'concerto' she devised for violin with voices by Jonathan Harvey, Thierry Pecou and Roxanna Panufnik. She received a further award for her 3-year collaboration 'FiddleSticks' with Ensemble Bash to commission and perform new works for solo violin and percussion by Anne Dudley, Tarik O'Regan and Stuart Jones as companion pieces to Lou Harrison Violin Concerto with Percussion Orchestra, which they performed without conductor, including Symphony Hall International Series and recorded.