Excursions, Op. 20, is the first published solo piano piece by Samuel Barber. Barber himself explains: These are ‘Excursions’ in small classical forms into regional American idioms. Their rhythmic characteristics, as well as their source in folk material and their scoring, reminiscent of local instruments are easily recognized. This is typical of neo-Romantic composers such as Barber. As Susan Carter explains in her dissertation, "The Piano Music of Samuel Barber", that “neo-Romantic composers returned to a style characterized by broad lyricism and dramatic expression.” She also states that the traditional structures of form from the eighteenth and nineteenth centuries were conserved while drawing upon a “contemporary technical vocabulary.” From a boogie-woogie style of a five-part rondo to a theme and variations of a well known cowboy ballad, and even to a barn-yard dance with a fiddler, Barber uses each style effectively and accurately, according to the neo-Romantic ideas. The third movement incorporates the melody from Streets of Laredo, an American folk song.

A ballade (; French: [balad]; and Latin: ballare ,pronounced [bälˈlʲäːrɛ]) refers to a one-movement instrumental piece with lyrical and dramatic narrative qualities reminiscent of such a song setting. In 19th century romantic music, a piano ballade is a genre of solo piano pieces written in a balletic narrative style, with lyrical and virtuosic elements being prominently featured.

In music, a chorale prelude or chorale setting is a short liturgical composition for organ using a chorale tune as its basis. It was a predominant style of the German Baroque era and reached its culmination in the works of J.S. Bach, who wrote 46 (with a 47th unfinished) examples of the form in his Orgelbüchlein, along with multiple other works of the type in other collections.

The Piano Sonata in E♭ minor, Op. 26, by the American composer Samuel Barber, was commissioned for the twenty-fifth anniversary of the League of Composers by American songwriters Irving Berlin and Richard Rodgers. Composed from 1947 to 1949, the sonata is in four movements. It was first performed by Vladimir Horowitz in December 1949 in Havana, Cuba, followed by performances in Washington, D.C. and New York City in January 1950. The sonata is regarded as a cornerstone of American piano literature and one of Barber's most significant achievements. Critics hailed it as a defining moment in mid-20th-century music, with The New York Times describing it as the "first sonata truly to come of age by an American composer of this period". Barber began composing the work in September 1947, completing the first movement later that year. However, progress was slow due to his demanding schedule, which included preparations for his ballet Medea and Knoxville: Summer of 1915. A planned retreat to the American Academy in Rome to focus on the sonata proved unproductive, as Barber was distracted by the postwar social scene and his interactions with intellectuals, Vatican insiders, and Italian culture. Barber returned to the United States in 1948 and completed the second movement by mid-August. Initially, Barber envisioned a three-movement work, but after sharing his progress with Horowitz, the pianist suggested a four-movement structure with a "flashy last movement". This advice led Barber to compose a virtuosic four-voice fugue as a final movement. Horowitz premiered the sonata in Havana, Cuba, on December 9, 1949. He followed this premiere with a private performance in New York in early January 1950 attended by prominent composers including Aaron Copland and Gian Carlo Menotti. The official US premiere took place at Constitution Hall in Washington, D.C., later that month, followed by a performance at New York's Carnegie Hall. The sonata was met with immediate widespread acclaim, and has since been performed and recorded often.

There is a long tradition in classical music of writing music in sets of pieces that cover all the major and minor keys of the chromatic scale. These sets typically consist of 24 pieces, one for each of the major and minor keys (sets that comprise all the enharmonic variants include 30 pieces). Examples include Johann Sebastian Bach's The Well-Tempered Clavier and Frédéric Chopin's 24 Preludes, Op. 28. Such sets are often organized as preludes and fugues or designated as preludes or études. Some composers have restricted their sets to cover only the 12 major keys or the 12 minor keys; or only the flat keys (Franz Liszt's Transcendental Études) or the sharp keys (Sergei Lyapunov's Op. 11 set). In yet another type, a single piece may progressively modulate through a set of tonalities, as occurs in Ludwig van Beethoven's 2 Preludes through all the Major Keys, Op. 39. The bulk of works of this type have been written for piano solo, but there also exist sets for piano 4-hands; two pianos; organ; guitar; two guitars; flute; recorder; oboe; violin solo; violin and piano; cello solo; cello and piano; voice and piano; and string quartet. There are examples of attempts to write full sets that, for one reason or another, were never completed (Josef Rheinberger's organ sonatas, Dmitri Shostakovich's string quartets, César Franck's L'Organiste).

This article lists compositions written for piano duo. The list includes works for piano four-hands and works for two pianos. Catalogue number and date of composition are also included. Ordering is by composer surname. A list of notable performers who played and recorded these works is at List of classical piano duos (performers).

"What Wondrous Love Is This" (often just referred to as "Wondrous Love") is a Christian folk hymn from the American South. Its text was first published in 1811, during the Second Great Awakening, and its melody derived from a popular English ballad (Roud number 5089). Today it is a widely known hymn included in hymnals of many Christian denominations.