Question: Who is an American composer who wrote "Could I leave you?"
Context: Stephen Joshua Sondheim ( ; born March 22, 1930) is an American composer and lyricist known for more than a half-century of contributions to musical theatre.  Sondheim has received an Academy Award, eight Tony Awards (more than any other composer, including a Special Tony Award for Lifetime Achievement in the Theatre), eight Grammy Awards, a Pulitzer Prize, a Laurence Olivier Award, and a 2015 Presidential Medal of Freedom.  He has been described by Frank Rich of "The New York Times" as "now the greatest and perhaps best-known artist in the American musical theater."  His best-known works as composer and lyricist include "A Funny Thing Happened on the Way to the Forum", "Company", "Follies", "A Little Night Music", "Pacific Overtures", "", "Merrily We Roll Along", "Sunday in the Park with George", "Into the Woods", "Assassins", and "Passion".  He also wrote the lyrics for "West Side Story" and "Gypsy". Transformations is a chamber opera in two acts by the American composer Conrad Susa with a libretto of ten poems by Anne Sexton from her 1971 book "Transformations", a collection of confessional poetry based on stories by the Brothers Grimm.  Commissioned by Minnesota Opera, the work, which is described by its composer as "An Entertainment in 2 Acts", had its world premiere on 5 May 1973 at the Cedar Village Theater in Minneapolis, Minnesota.  Anne Sexton, who had worked closely with Susa on the libretto, was in the audience.  It went on to become one of the most frequently performed operas by an American composer with its chamber opera format of eight singers and an instrumental ensemble of eight musicians making it particularly popular with smaller opera companies and conservatories.  The 2006 revival production of "Transformations" at the Wexford Opera Festival won the "Irish Times" Theatre Award for Best Opera Production. Stringmusic is a musical composition for string orchestra by the American composer Morton Gould.  It was commissioned by the National Symphony Orchestra and was premiered at the Kennedy Center by the NSO on March 10, 1994.  The piece is dedicated to the conductor Mstislav Rostropovich upon his leave. Barbara Kolb (b. Hartford, Connecticut, February 10, 1939) is an American composer.  Her music uses sound masses and often creates vertical structures through simultaneous rhythmic or melodic units (motifs or figures).  Barbara's musical styling can be identified by her use of colorful textures, impressionistic touch, and atonal vocabulary, with influences stemming from literary and visual arts.  She was the first American woman composer to win the Rome Prize.  She received her B.M. (cum laude, 1961) and M.M. degrees (1964) from the Hartt College of Music (now The Hartt School) at the University of Hartford, and studied with Arnold Franchetti, Lukas Foss and Gunther Schuller.  Following her various degrees, Kolb relocated to Vienna, Austria from 1966-1967 with a Fulbright Fellowship grant.  She was the first female American composer to win the Rome Prize [Prix de Rome], in 1969.  From 1979 - 1982, Kolb served as the artistic director of contemporary music at the Third Street Music School Settlement, where she presented the "Music New to New York" concert series.  Additionally, she has had a professional teaching career teaching at Rhode Island College and Eastman School of Music as a visiting professor in Composition.  A selection of Barbara's compositions were featured at the Kennedy Center, performed by the "Theatre Chamber Players" as part of the Boston Modern Orchestra Project.  However, Kolb was not only known as a composer; but she was also proficient at the Eb clarinet. "I Couldn't Leave You If I Tried" is a song written and performed by American country music artist Rodney Crowell.  It was released in May 1988 as the second single from Crowell's album "Diamonds & Dirt".  "I Couldn't Leave You If I Tried" was the first of his five number one country singles.  The single went to number one for one week and spent a total of thirteen weeks on the country chart. Henry Holden Huss (June 21, 1862 in Newark, New Jersey – September 17, 1953 in New York City) was an American composer, pianist and music teacher.  Huss grew up in New York City, the son of German immigrant parents.  After studying piano and organ locally with a teacher who had trained at the Leipzig Conservatory, Huss traveled to Munich to study at the Royal Conservatory with Josef Rheinberger.  His fellow students at the Royal Music School in Munich included Arthur Whiting and H. W. Parker.  After graduating, he returned to the States and embarked on a career as a touring piano virtuoso.  As a composer, he was regarded as one of the best of his generation by those who counted, but unfortunately, it was at a time when American composers could rarely get a hearing for their works. Richard Niles is an American composer, arranger, record producer, guitarist, broadcaster, and journalist.  He has lived in London since 1975.  Because of his extensive work across many genres, "Sound on Sound" magazine referred to him as "one of the most versatile men in modern music".  Jazz guitarist Pat Metheny wrote, "Richard Niles is one of the best composer/arrangers around and an exciting musical force."  Paul McCartney wrote, "Richard Niles is a great orchestrator and musician and was a great pleasure to work with." The American Composer Series is an ongoing performance series in the cabaret revue format, paying tribute to the greatest composers of popular American music on the American scene, particularly those composers associated with Tin Pan Alley.  Launched by musical director Earl Wentz in 2000 with a tribute to Ray Henderson (composer of mega-hits “Life is Just a Bowl of Cherries,” “Bye Bye Blackbird,” “Button Up Your Overcoat,” “The Birth of the Blues” and others) titled "It’s the Cherries", the series has continued to add new shows to its repertoire at the rate of one or two per year.  As of 2009, the American Composer Series had created some 15 original revue tributes, many of them returning for multiple runs over the years. "Could I Leave You?"  is a song written by Stephen Sondheim for the 1971 musical "Follies" for the character Phyllis. Edmund Severn (December 10, 1862 – May 14, 1942) was an American composer and violinist.  Born in England, in Nottingham, he moved to the United States at four, settling in Hartford, Connecticut and studying violin with his father; he later studied music in Berlin.  There he studied the Joachim bowing technique.  As a composer he wrote mainly orchestral music, as well as many pieces for his instrument, including a concerto; he also wrote three string quartets.  He died in Melrose, Massachusetts. His most famous work is his "Polish Dance" for violin and piano.
Answer: Stephen Sondheim