Thea Musgrave, the Scottish-born composer who turns 99 next year, remains prolifically active, with a new bassoon concerto for soloist Amy Harman receiving its Proms premiere this weekend. The piece continues the "dramatic-abstract" approach that has defined much of her career, in which orchestral players are treated not as a uniform ensemble following a conductor but as individual characters who can defy, move around and interact independently, giving her music an unusually theatrical, visceral quality.

The technique traces back to a dream in the 1960s in which a clarinettist in an orchestra stood up and refused to sit down, which directly inspired her 1967 Concerto for Orchestra for the City of Birmingham Symphony Orchestra. She developed the idea further in works such as her Clarinet Concerto, Horn Concerto and Two's Company, in each case having soloists move physically among the ensemble. Her new bassoon concerto, Out of the Darkness, was written for Amy Harman after violinist and oboist Nicholas Daniel introduced the pair last year, and premieres at the Proms on 23 August; Musgrave also has a new opera, Orlando: An Escapade, based on Virginia Woolf's novel, due at the Buxton festival next year.