His music has a haunting, searching quality, as if a deeply personal question is being asked, but never answered (Tait 2007, see below). In the song cycle "Discovery", the surrealistic poetic language of Denton Welch ("What are you in the morning when you wake? A quacking duck, a quacking drake?") is the ideal spark for Ferguson to express such private questioning in his aphoristic, fleeting settings (Tait). Ferguson produced what (according to Tait) is probably one of the greatest British solo piano works of the twentieth century, the stormy and passionate Piano Sonata, Op. 8, inspired by the death of a friend. Of his two violin sonatas, the second emerged after a long silence just after World War II; the ferocious energy of its finale has a spirit of escape and liberation, a suppressed voice finally speaking (Tait) (Ferguson had not had the time to compose during the war due to his other commitments). His miniatures, such as the "Four Short Pieces" for clarinet and piano and the "Three Sketches" for flute and piano, have a crystalline intensity, as if hinting at much larger works (Tait) – Anton Webern was a composer he admired, even if stylistically Ferguson's own work belongs to the sound world of twentieth century Romanticism. Ferguson was always highly self-critical as a composer: after writing the large choral work "The Dream of the Rood" in 1958-9, he received a commission to write a string quartet. It was during the composition of this that he felt he was merely repeating his previous work, so he destroyed the sketches and gave up composing, saying that in his relatively few works he had said all he wanted to say.