representation of unconscious processes." Similarly, Diana Hume George claimed that Blake can be seen as a precursor to the ideas of Sigmund Freud. Blake had an enormous influence on the beat poets of the 1950s and the counterculture of the 1960s, frequently being cited by such seminal figures as beat poet Allen Ginsberg, songwriters Bob Dylan, Jim Morrison, Van Morrison, and English writer Aldous Huxley. The Pulitzer-winning composer William Bolcom set Songs of Innocence and of Experience to music, with different poems set to different styles of music, "from modern techniques to Broadway to Country/Western" and reggae. Much of the central conceit of Philip Pullman's fantasy trilogy His Dark Materials is rooted in the world of Blake's The Marriage of Heaven and Hell. Blake also features as a relatively significant character in Brian Catling's fantasy novel The Erstwhile, where his visions of angelic beings are figured into the story. Canadian music composer Kathleen Yearwood is one of many contemporary musicians that have set Blake's poems to music. After World War II, Blake's role in popular culture came to the fore in a variety of areas such as popular music, film, and the graphic novel, leading Edward Larrissy to assert that "Blake is the Romantic writer who has exerted the most powerful influence on the twentieth century." Exhibitions Major recent exhibitions focusing on William Blake include: The Ashmolean Museum's (Oxford) exhibition William Blake: Apprentice and Master, open from December 2014 until March 2015, examined William Blake's formation as an artist, as well as his influence on young artist-printmakers who gathered around him in the last years of his life. The National Gallery of Victoria's exhibition William Blake in summer 2014 showcased the Gallery's collection of works by William Blake which includes spectacular watercolours, single prints and illustrated books. The Morgan Library & Museum exhibition William Blake's World: "A New Heaven Is Begun", open from September 2009 until January 2010, included more than 100 watercolours, prints, and illuminated books of poetry. An exhibition at Tate Britain in 2007–2008, William Blake, coincided with the two hundred and fiftieth anniversary of William Blake's birth and included Blake works from the Gallery's permanent collection, but also private loans of recently discovered works which had never before been exhibited. The Scottish National Gallery 2007 exhibition William Blake coincided with the two hundred and fiftieth anniversary of William Blake's birth and featured all of the Gallery's works