Joseph Arthur (born September 28, 1971) is an American singer-songwriter and artist from Akron, Ohio, United States. He is best known for his solo material, and as a member of Fistful of Mercy and RNDM. Combining poetic lyrics with a layered sonic palette, Arthur has built his reputation over the years through critically acclaimed releases and constant touring; his unique solo live performances often incorporate the use of a number of distortion and loop pedals, and his shows are recorded live at the soundboard and made available to concertgoers immediately following the show on recordable media. Arthur was discovered by Peter Gabriel in the mid-1990s, and signed to Gabriel's Real World label as the first North American artist on the label's roster.

Arthur signed a new recording contract with Vector Recordings and began recording his fourth studio album, Our Shadows Will Remain across New Orleans, New York City, London, and Prague. The album was released in September 2004, and was Arthur's first album to feature string arrangements, provided by the City of Prague Philharmonic. The album was released to widespread critical acclaim; Allmusic's Thom Jurek awarded the album 4.5 out of 5 stars, praising that, "Arthur is in a class of his own and Our Shadows Will Remain is a monstrous, memorable outing, his finest moment in a career that is thus far full of them." Entertainment Weekly gave the album an A rating, hailing the album as "especially forceful and cohesive"; The Guardian hailed that Joseph "might just be a genuine mad genius"; Stylus Magazine gave the album an A- rating; and Chris Rubin of Rolling Stone named Our Shadows Will Remain as the number 1 album of the year 2004 in the year-end critics' pick list. Arthur toured the US alone and with Joan Wasser to promote the album, and a new EP called And the Thieves Are Gone, which collected unreleased tracks from the Shadows recording sessions, came out in December. Shortly afterward, Arthur went on a brief tour of Europe with R.E.M.. Our Shadows Will Remain was picked up by 14th Floor Records for distribution in the United Kingdom in 2005, which yielded the release of four singles: "Can't Exist" in July, "Even Tho" in September, "Devil's Broom" in February 2006 to coincide with his first headlining appearance at London's Shepherds Bush Empire, and a reissue of "Can't Exist" in May 2006, although none of the singles charted on the UK Singles Chart. In August 2006, Joseph was invited to help launch the project A River Blue, where a group of young people in northern Uganda were brought together to participate in a music, drama, and art festival. Joseph also recorded the song "A River Blue" for the foundation.

Using a quote from the above article, answer the following question: What did he accomplish in 2006?
first headlining appearance at London's Shepherds Bush Empire,