Gustav Holst in the context of "Royal College of Music"

Vocal music is a type of singing performed by one or more singers, either with instrumental accompaniment or without instrumental accompaniment (a cappella), in which singing provides the main focus of the piece. Music which employs singing but does not feature it prominently is generally considered to be instrumental music (e.g. the wordless women's choir in the final movement of Holst's symphonic work The Planets) as is music without singing. Music without any non-vocal instrumental accompaniment is referred to as a cappella.

Vocal music typically features sung words called lyrics, although there are notable examples of vocal music that are performed using non-linguistic syllables, sounds, or noises, sometimes as musical onomatopoeia, such as jazz scat singing. A short piece of vocal music with lyrics is broadly termed a song, although in different styles of music, it may be called an aria or hymn.

Chamber opera is a designation for operas written to be performed with a chamber ensemble rather than a full orchestra. Early 20th-century operas of this type include Paul Hindemith's Cardillac (1926). Earlier small-scale operas such as Pergolesi's La serva padrona (1733) are sometimes known as chamber operas.

Other 20th-century examples include Gustav Holst's Savitri (1916). Benjamin Britten wrote works in this category in the 1940s when the English Opera Group needed works that could easily be taken on tour and performed in a variety of small performance spaces. The Rape of Lucretia (1946) was his first example in the genre, and Britten followed it with Albert Herring (1947), The Turn of the Screw (1954) and Curlew River (1964). Other composers, including Hans Werner Henze, Harrison Birtwistle, Thomas Adès, George Benjamin, William Walton, and Philip Glass have written in this genre.

Christina Georgina Rossetti (5 December 1830 – 29 December 1894) was an English writer of romantic, devotional and children's poems, including "Goblin Market" and "Remember". She also wrote the words of two Christmas carols well known in Britain: "In the Bleak Midwinter", later set by Gustav Holst, Katherine Kennicott Davis, and Harold Darke, and "Love Came Down at Christmas", also set by Darke and other composers. She was a sister of the artist and poet Dante Gabriel Rossetti and features in several of his paintings. Some of her early poetry, such as "Goblin Market", was influenced by the Pre-Raphaelite movement.

Elliott Cook Carter Jr. (December 11, 1908 – November 5, 2012) was an American modernist composer who was one of the most respected composers of the second half of the 20th century. He combined elements of European modernism and American "ultra-modernism" into a distinctive style with a personal harmonic and rhythmic language, after an early neoclassical phase. His compositions are performed throughout the world, and include orchestral, chamber music, solo instrumental, and vocal works. Carter was the recipient of many awards – he was twice awarded the Pulitzer Prize for his string quartets. He also wrote the large-scale orchestral triptych Symphonia: sum fluxae pretium spei.

Carter was born in New York City. He developed an interest in modern music in the 1920s. He was later introduced to Charles Ives, and he soon came to appreciate the American ultra-modernists. After studying at Harvard University with Edward Burlingame Hill, Gustav Holst and Walter Piston, he studied with Nadia Boulanger in Paris in the 1930s, then returned to the United States. Carter was productive in his later years, publishing more than 40 works between the ages of 90 and 100, and over 20 more after he turned 100 in 2008. He completed his last work, Epigrams for piano trio, on August 13, 2012.

The Planets, Op. 32, is a seven-movement orchestral suite by the English composer Gustav Holst, written between 1914 and 1917. In the last movement the orchestra is joined by a wordless female chorus. Each movement of the suite is named after a planet of the Solar System and reflects its astrological significance.

The premiere of The Planets was at the Queen's Hall, London, on 29 September 1918, conducted by Holst's friend Adrian Boult before an invited audience of about 250 people. Three concerts at which movements from the suite were played were given in 1919 and early 1920. The first complete performance at a public concert was given at the Queen's Hall on 15 November 1920 by the London Symphony Orchestra conducted by Albert Coates.