Question: What's the current population of James Matheson's birth city?

full_context: Document 1: Orchestra 2001: James Freeman founded Orchestra 2001 in 1988 as its artistic director and conductor, and continues to serve in both posts. The ensemble is noted for performances of works by composers based in the Philadelphia region, in particular George Crumb. Orchestra 2001 has performed many of Crumb's works since the ensemble's inception. These have included premieres of his "American Songbooks" series of compositions and other works such as "Voices from a Forgotten World". The orchestra has also premiered compositions by other composers such as:
Document 2: Des Moines, Iowa: On September 22, 1851, Des Moines was incorporated as a city; the charter was approved by voters on October 18. In 1857, the name ``Fort Des Moines ''was shortened to`` Des Moines'', and it was designated as the second state capital, previously at Iowa City. Growth was slow during the Civil War period, but the city exploded in size and importance after a railroad link was completed in 1866.
Document 3: United States Artists: United States Artists (USA) is an independent nonprofit and nongovernmental philanthropic organization based in Chicago and dedicated to supporting the work of living American artists by the granting of cash awards, called USA Fellowships. It was founded in 2005 with initial funding from the Ford Foundation, the Rockefeller Foundation, The Prudential Foundation, and the Rasmuson Foundation, and the first set of 50 fellowships were announced in 2006. The organization is governed by a Board of Directors and receives additional funding from several major American foundations, corporate partners, and private citizens.
Document 4: Des Moines metropolitan area: The Des Moines metropolitan area, officially known as the Des Moines -- West Des Moines, IA Metropolitan Statistical Area (MSA), consists of five counties in central Iowa, United States: Polk, Dallas, Warren, Madison, and Guthrie. The 2010 census population of these counties was 569,633, and the 2017 estimated population was 645,911.
Document 5: James Matheson (composer): James Matheson (born 1970 in Des Moines, Iowa) is an American composer. His works have been commissioned and performed by the Albany Symphony Orchestra, Chicago Symphony Orchestra, Los Angeles Philharmonic, New York Philharmonic, Borromeo String Quartet, Carnegie Hall and the St. Lawrence String Quartet. In December 2011, he received the Charles Ives Living from the American Academy of Arts and Letters, an award providing him with $100,000 for two years (2012-2014). Previously, he received the Academy’s Goddard Lieberson Fellowship in 2008 and Hinrichsen Award in 2002. He has also received awards from the Civitella Ranieri, Bogliasco and Sage Foundations, ASCAP, and the Robbins Prize. He was executive director of the MATA Festival of New Music in New York from 2005-2007 and has been a fellow at the Aspen Music Festival. Since September 2009, he has been the director of the Los Angeles Philharmonic’s Composer Fellowship Program.
Document 6: Saylorville, Iowa: Saylorville is a census-designated place (CDP) in Polk County, Iowa, United States. The population was 3,301 at the 2010 census. It is part of the Des Moines–West Des Moines Metropolitan Statistical Area. The Saydel Community School District is located in this area. The unincorporated community of Marquisville is in this area.
Document 7: Middletown, Iowa: Middletown is a city in Des Moines County, Iowa, United States. The population was 318 at the 2010 census. It is part of the Burlington, IA–IL Micropolitan Statistical Area.
Document 8: Double Sextet: Double Sextet is a composition by Steve Reich scored for two sextets of flute, clarinet, violin, cello, vibraphone and piano. It won the 2009 Pulitzer Prize for Music, the first for the composer. With funds from the Carnegie Hall Corporation, The Abe Fortas Memorial Fund of the John F. Kennedy Center for the Performing Arts, Liverpool Culture Company – European Capital of Culture 2008, The Modlin Center for the Arts at the University of Richmond, Orange County Performing Arts Center, The University of Cincinnati College-Conservatory of Music – Music 08 Festival the piece was commissioned in 2007 by Eighth Blackbird who performed its premiere in 2008, at the University of Richmond in Virginia.. The Liverpool Culture Company (Gordon Ross, music programme manager) was the only non-US commissioning organisation and hosted the rest-of-the-world premiere at St. George's Concert Room, Liverpool on the 21st of November 2008 as part of Liverpool's European Capital of Culture celebrations.
Document 9: Des Moines, Iowa: Age spread: 24.8% under the age of 18, 10.6% from 18 to 24, 31.8% from 25 to 44, 20.4% from 45 to 64, and 12.4% who were 65 years of age or older. The median age was 34 years. For every 100 females, there were 93.8 males. For every 100 females age 18 and over, there were 90.5 males.
Document 10: Johnston, Iowa: Johnston is a city in Polk County, Iowa, United States. The population was 17,278 in the 2010 census, an increase of almost 100% from the 8,649 population in the 2000 census. It is part of the Des Moines–West Des Moines Metropolitan Statistical Area.
Document 11: Cedar Rapids, Iowa: As of the 2010 United States Census, the city population was 126,326. The estimated population of the three - county Metropolitan Statistical Area, which includes the nearby cities of Marion and Hiawatha, was 255,452 in 2008. Cedar Rapids is an economic hub of the state, located in the core of the Interstate 380.
Document 12: James Behr: Pianist and composer James Behr is a graduate of The Juilliard School (MM and BM) and has performed throughout the U.S. Behr won first prize in the 2013 Bradshaw & Buono International Piano Competition featuring a solo performance at Carnegie Hall (Weill). He served as Classical Artist in Residence for The Florida Symphonic Pops (aka The Boca Raton Pops), performed on TV show "Talk of the Town," and was a featured soloist on radio, including WNYC and WXEL programs "Keyboard Artists" and "Morning Scherzo." A Steinway Artist and adjunct professor at Manhattan College, Behr has performed as solo pianist at Alice Tully Hall (Lincoln Center), The Chautauqua Festival, and as concerto soloist with The Virginia Symphony Orchestra, The Naples Philharmonic, The Miami City Ballet, and The North Miami Symphony. He received scholarship awards from Juilliard and The Chautauqua Music Festival. Behr was also a prizewinner in the Society of American Musicians Competition, IL; Cullowhee Music Festival Competition, NC; Boca Raton Music Guild Competition, FL; Five Towns Music Festival Competition, NY; and Chicago Music Club Piano Competition, IL.
Document 13: New Philharmonia Orchestra of Massachusetts: The motto of the orchestra is "Music for All". In that spirit, the orchestra conducts active outreach programs in the Boston public schools and has strong links to other local school systems and civic organizations. The 2007-2008 season concluded with a benefit concert at the Kennedy Library attended by the mayor of Boston, Thomas Menino, honoring the orchestra's partnership with John Hancock financial services. Under this partnership, members of the orchestra have been offering supplemental music education programs in the Oliver H. Perry elementary school in South Boston.
Document 14: British Academy of Songwriters, Composers, and Authors: In 1999 The Association of Professional Composers (APC) and the Composers' Guild of Great Britain (CGGB) merged with the British Academy of Songwriters, Composers and Authors to provide a single, more powerful amalgamated organisation to represent its membership. The organization's current name was adopted in March, 2009. Sir Tim Rice was elected first president, and Guy Fletcher and David Stoll served as joint chairs of a nine-member Board of Directors. Three executive committees were established to administer Pop and Theatrical Music, Concert Music and Media. BASCA now has four genre committees representing Songwriters, Classical, Jazz and Media composers.
Document 15: Indianola, Iowa: Indianola is a city in Warren County, Iowa, United States, 18 miles south of Des Moines, Iowa. The population was 14,782 at the 2010 census. It is the county seat of Warren County.
ground_truth: 645,911
sub_queries: James Matheson >> place of birth Answer: Des Moines
what is the population of the Des Moines area Answer: 645,911