Question: Gustav Mahler composed a beautiful piece performed by the Bach-Elgar Choir. What is the name of that piece??

full_context: Document 1: Handel Choir of Baltimore: The Handel Choir of Baltimore is a choir and oratorio society based in Baltimore, Maryland, which has been performing since the 1930s. The ensemble is known for its annual performances of George Frideric Handel's "Messiah", an unbroken tradition since 1935. During the tenure of Melinda O'Neal, Artistic Director and Conductor from 2004 to 2013, the Choir inaugurated the Handel Period Instrument Orchestra, an historically informed performance group. In 2007, the Handel Choir of Baltimore and the Handel Society of Dartmouth College commissioned a work by Jonathan Leshnoff which came to be known as "Requiem for the Fallen". In February 2008, Handel Choir joined with the Baltimore Chamber Orchestra to present the premiere performance of the Requiem.
Document 2: Symphony No. 2 (Mahler): Symphony No. 2 by Gustav Mahler, known as the Resurrection Symphony, was written between 1888 and 1894, and first performed in 1895. Apart from the Eighth Symphony, this symphony was Mahler's most popular and successful work during his lifetime. It was his first major work that established his lifelong view of the beauty of afterlife and resurrection. In this large work, the composer further developed the creativity of "sound of the distance" and creating a "world of its own", aspects already seen in his First Symphony. The work has a duration of eighty to ninety minutes and is conventionally labelled as being in the key of C minor; the "New Grove Dictionary of Music and Musicians" labels the work's tonality as C minorE♭ major.
Document 3: Aeolian Singers: The Aeolian Singers, president Peter Skellern, musical director Stephen Jones, rehearsal pianist Anna Le Hair, was established in 1963. With about 80 members, it is Hemel Hempstead's largest mixed-voice chorus. While based in Hertfordshire, the singers also perform in major London concert halls and in other parts of Europe. In recent years they have performed in Ghent, Paris and Provence and visited Mannheim in October 2006, where they performed in two concerts together with the Konzertchor der Stadt Mannheim. They have a very wide repertoire ranging from Renaissance to contemporary music, and have given several first performances. They also have a tradition of community and youth involvement.
Document 4: Michigan State University Children's Choir: The Michigan State University Children's Choir (MSUCC) is a Grammy Award-winning children's choir located in East Lansing, Michigan. In 2009, Kristin Zaryski was named director, succeeding the founder of the choir, Mary Alice Stollak. Following Ms. Zaryski, Kyle Zeuch was named Director. Most choristers in the choir come from the two other children's choirs in the program, the CMS Singers, and Preparatory Choir. The choir has performed at Carnegie Hall in New York City, Orchestra Hall in Detroit, Symphony Center in Chicago, and the Kennedy Center, in Washington D.C. In 2006, the choir won two Grammy Awards for their contributions to William Bolcom's "Songs of Innocence and of Experience": Best Choral Performance and Best Classical Album .
Document 5: Symphony No. 7 (Mahler): Symphony No. 7 by Gustav Mahler was written in 1904–05, with repeated revisions to the scoring. It is sometimes referred to by the title Song of the Night (German: "Lied der Nacht" ), which Mahler never knew (and certainly would be unlikely to have sanctioned). Although the symphony is often described as being in the key of E minor, its tonal scheme is more complicated. The symphony's first movement moves from B minor (introduction) to E minor, and the work ends with a rondo finale in C major. Thus, as Dika Newlin has pointed out, "in this symphony Mahler returns to the ideal of 'progressive tonality' which he had abandoned in the Sixth". The complexity of the work's tonal scheme was analysed in terms of "interlocking structures" by Graham George.
Document 6: Symphony No. 2 (Bruckner): Anton Bruckner’s Symphony No. 2 in C minor, sometimes known as the “Symphony of Pauses,” was completed in 1872, premiered in Vienna the following year with Bruckner himself on the podium, and given a substantial revision in 1877. (The "Internationale Bruckner-Gesellschaft" thus recognizes two versions.) The work was also adjusted by the composer right before its premiere as well as in 1876 and 1892. The composition date of 1872 places this music after the Symphony "No. 0" in D minor, which was itself composed "after" the Symphony No. 1 in C minor. The Second is the only numbered Bruckner symphony without a dedication; Franz Liszt tacitly rejected the dedication, and Richard Wagner chose the Symphony No. 3 in D minor when offered both works.
Document 7: Symphony No. 1 (Mahler): The Symphony No. 1 in D major by Gustav Mahler was mainly composed between late 1887 and March 1888, though it incorporates music Mahler had composed for previous works. It was composed while Mahler was second conductor at the Leipzig Opera, Germany. Although in his letters Mahler almost always referred to the work as a symphony, the first two performances described it as a symphonic poem or tone poem. The work was premièred at the Vigadó Concert Hall, Budapest, in 1889, but was not well received. Mahler made some major revisions for the second performance, given at Hamburg in October 1893; further alterations were made in the years prior to the first publication, in late 1898. Some modern performances and recordings give the work the title "Titan", despite the fact that Mahler only used this label for two early performances, and never after the work had reached its definitive four-movement form in 1896.
Document 8: Bruce Carey: Bruce Anderson Carey (16 November 1876 – 8 May 1960) was a Canadian choir conductor, baritone, and music educator. He began his career in Hamilton, Ontario, where he notably founded the Bach-Elgar Choir in 1905. After directing that ensemble for seventeen years, he moved to Philadelphia, Pennsylvania in the United States where he was conductor of two famous choruses: the Mendelssohn Club and The Bach Choir of Bethlehem.
Document 9: Symphony No. 6 (Mahler): Symphony No. 6 in A minor by Gustav Mahler is a symphony in four movements, composed in 1903 and 1904 (revised 1906; scoring repeatedly revised). Mahler conducted the work's first performance at the concert hall in Essen on May 27, 1906. It is sometimes referred to by the nickname "Tragische" ("Tragic"). Mahler composed the symphony at what was apparently an exceptionally happy time in his life, as he had married Alma Schindler in 1902, and during the course of the work's composition his second daughter was born. This contrasts with the tragic, even nihilistic, ending of No. 6. Both Alban Berg and Anton Webern praised the work when they first heard it. Berg expressed his opinion of the stature of this symphony in a 1908 letter to Webern:
Document 10: Symphony No. 5 (Beethoven): The Symphony No. 5 in C minor of Ludwig van Beethoven, Op. 67, was written between 1804–1808. It is one of the best-known compositions in classical music, and one of the most frequently played symphonies. First performed in Vienna's Theater an der Wien in 1808, the work achieved its prodigious reputation soon afterward. E. T. A. Hoffmann described the symphony as "one of the most important works of the time". The symphony consists of four movements. The first movement is Allegro con brio; the second movement is Andante con moto; the third movement is a Scherzo Allegro; the fourth movement is Allegro.
Document 11: Bach-Elgar Choir: The Bach-Elgar Choir is a community chorus of long standing in Hamilton, Ontario. The Choir is composed of accomplished amateur singers from Hamilton and neighbouring cities of Burlington, Oakville, Mississauga and Simcoe. Notable performances by the ensemble include the North American première of Verdi's "Requiem" and the Canadian premières of Górecki's "Miserere" and Mahler's "Symphony No. 2" (the Resurrection). The choir has had several distinguished directors throughout its history and has performed in several notable venues including Roy Thomson Hall in Toronto, the Brantford's Sanderson Centre, with the Buffalo Philharmonic Orchestra, and at the Boris Brott Summer Festival. The choir enjoys frequent guest appearances with the Hamilton Philharmonic Orchestra.
Document 12: Magnum Chorum: Magnum Chorum is a choral ensemble based in the Twin Cities of Minnesota. Magnum Chorum performs sacred choral music in cathedrals and sanctuaries throughout the Midwest. The 65 voice auditioned choir presents concerts, commissions new sacred works, makes recordings, and provides music for worship. Founded in 1991 in the choral tradition of St. Olaf College, membership was originally limited to St. Olaf graduates, but since 2005, auditions are open to singers devoted to excellence in choral music. Magnum Chorum’s name is intended to convey the importance of the choir in expressing the divine and infinite through voice, music, and text.
Document 13: Symphony No. 2 (Raff): Symphony No. 2 in C major, Op. 140, was composed by Joachim Raff in Weimar in 1866. It is one of the three Raff symphonies that does not carry a descriptive title. It is dedicated to Ernest II, Duke of Saxe-Coburg and Gotha. It was premiered in Weimar in 1867 and was published two years later in Mainz. A few years later the symphony received its second performance in the Leipzig Gewandhaus under Raff's baton. A typical performance lasts for about 37 minutes.
Document 14: Vancouver Chamber Choir: The Vancouver Chamber Choir is a Canadian choir performing in Vancouver, British Columbia. It was founded in 1971 and has commissioned and premiered more than 170 new choral works in over four decades. The choir performs at home and abroad and has received many honours and distinctions from around the world. The choir has toured throughout North America as well as Asia and Europe.
Document 15: Symphony No. 8 (Mahler): The Symphony No. 8 in E-flat major by Gustav Mahler is one of the largest-scale choral works in the classical concert repertoire. Because it requires huge instrumental and vocal forces it is frequently called the "Symphony of a Thousand", although the work is normally presented with far fewer than a thousand performers and the composer did not sanction that name. The work was composed in a single inspired burst, at Maiernigg in southern Austria in the summer of 1906. The last of Mahler's works that was premiered in his lifetime, the symphony was a critical and popular success when he conducted the Munich Philharmonic in its first performance, in Munich, on 12 September 1910.
ground_truth: Symphony No. 2