The accordion is in a wide variety of musical genres, mainly in traditional and popular music. In some regions, such as in Europe and North America, it has become mainly restricted to traditional, folk and ethnic music. Nonetheless, the button accordion (melodeon) and the piano accordion are widely taught and played in Ireland, and have remained a steady fixture within Irish traditional music, both in Ireland and abroad, particularly in the United States and Great Britain. Numerous virtuoso Irish accordion players have recorded many albums over the past century or so; the earliest Irish music records were made in the 1920s, in New York City, by fiddler and Sligo immigrant Michael Coleman, widely considered to have paved the way for other traditional musicians to record themselves. Accordions are also played within other Celtic styles (such as in Scotland, Cornwall and Brittany), as well as in English traditional music, American traditional music, polka, Galician folk music, and Eastern European folk music.

In northern Europe and Scandinavia, despite these musical traditions being somewhat fiddle-heavy, accordions may still be heard from time to time in the music of Denmark, Finland, Norway, Sweden and the Baltic states; the sound of accordion and fiddle played together has been said to be complementary.

In other regions, such as Mexico and Latin America, the instrument is very popular in genres like Norteño, Conjunto, and corridos; in Brazil, it is a fixture in popular music styles, such as Sertanejo and Forró.

The accordion is also used in Western art music, such as jazz (most famously the North American accordionist Frank Marocco) and classical music.Henry Doktorski, CD booklet notes for "Guido Deiro: Complete Recorded Works, Vol. 1", Archeophone Records (2007).

Use in traditional music

After the invention of the accordion in 1829, its popularity spread throughout the world, in no small measure due to the polka craze. "Once the polka became a craze in Paris and London during the spring of 1844, it diffused rapidly to the rest of the world. . . . In March 1844, polka-mania took Paris: common people, servants, workers and, one assumes, anyone else who wasn't too stuffy were dancing the polka in the streets of the capital and soon in Bordeaux and other French cities as well. A week or so later it took London by storm. And from these two great centers of fashion, empire, and influence, the polka diffused rapidly upward into the rest of French and English society and outward to the rest of the world."Charles Keil, Angeliki V. Keil, Dick Blau, Polka Happiness (Temple University Press, Philadelphia: 1992), 9, 11.

Except for a brief moment in time during the 1830s and 1840s when the accordion was heard by French aristocracy during Salon music concerts, the instrument has always been associated with the common people. The accordion was spread across the globe by the waves of Europeans who emigrated to various parts of the world in the late 19th century and early 20th century.

The mid-19th-century accordion became a favorite of folk musicians for several reasons: "The new instrument's popularity [among the common masses] was a result of its unique qualities. Firstly, it was much louder than all the older folk instruments put together. It could easily be heard in even the wildest pub above the stomping of dancing feet. It was also the prototype of a 'one man band' with bass and chords on the left-hand side and buttons for the melody on the right, and you could still sing along and beat the rhythm with your feet. The instrument needed no tuning and was always ready to play, but the most ingenious thing about the early one-row squeezebox was that you couldn't play it really badly. Even if you lost the melody it still sounded fine."Christoph Wagner, "A Brief History of How the Accordion Changed the World", CD booklet notes for Planet Squeezebox, performed by various artists, (Roslyn, New York: Ellipsis Arts, 1995), 6.

Since its invention, the accordion has become popularly integrated into a lot of varying traditional music styles all over the world, ranging from the European polka and the Colombian Vallenato to Korean trot music. See the list of traditional music styles that incorporate the accordion. Although rarely seen, some early swing band scores have the piano part marked "Piano/Piano Accordion."

It is a traditional instrument in Brazilian music, specifically baião of the northeast. Luiz Gonzaga is called the king of baião.

The accordion is featured heavily in traditional Egyptian music, particularly baladi styles.

Sometimes, certain traditional music styles may even be tied to a certain type of accordion, like the Schrammel accordion for Schrammelmusik, the Trikitixa for Basque music, or the diatonic button accordion in Mexican conjunto and norteño music. It would be hard to name one country in which the accordion did not play a significant role in its music tradition. It has even been idealized in literature.Wallace, Len. "The Accordion - The People's Instrument" (1989) Online PDF

Use in popular music

The accordion was heard frequently in popular music beginning around 1910 until about 1960. With rise of the popularity of the guitar (in particular the electric guitar) and rock music, the popularity of the accordion in pop music in Europe and North-America declined strongly. In some countries however, such as Brazil and Mexico, the accordion continues to be a fixture in pop music and its popularity is undiminished.

This half century is often called the "Golden Age of the Accordion." Three players, more than any others, inaugurated this era of popularity for the instrument, all Italian immigrants to the United States: Pietro Frosini, and the two brothers Count Guido Deiro and Pietro Deiro.For a biography of Guido and Pietro Deiro, see Henry Doktorski's The Brothers Deiro and Their Accordions, The Classical Free-Reed, Inc. (2005). All three players were celebrities on the Vaudeville circuits and performed throughout North America, Europe and Australia during the age of Vaudeville. They recorded hundreds of 78 RPM records for the Victor Talking Machine Company, Columbia Records, Decca Records, Edison Records and Cylinders, and other labels.The Golden Age of the Accordion, Flynn, Davison and Chavez, eds., 3rd edition (Schertz, Texas: Flynn Associates Publishing Co., 1992) Guido Deiro was the most successful and famous accordionist during the 1910s and 1920s, and lived a life filled with celebrity, luxury, fast cars, and fast women.Henry Doktorski, The Brothers Deiro and Their Accordions (The Classical Free-Reed, Inc., Oakdale, Pennsylvania: 2005) Many popular bands, such as the Paul Whiteman Orchestra, employed staff accordionists.Henry Doktorski, "The Accordion and Gershwin's Rhapsody in Blue", Music Theory: Explorations and Applications, Vol. VII (1999) Mary Pappert School of Music, Duquesne University Publication. See also: http://henrydoktorski.com/misc/gershwin.html.

After most Vaudeville theaters closed during the Great Depression, accordionists still found work during the 1930s teaching and performing for radio. Charles Magnante is considered one of the greatest American popular accordionists. At the peak of his career, he played 30 live radio broadcasts and eight studio sessions each week.Helmi Strahl Harrington, editor, The Charles Magnante Story: The Autobiography of America's Great Accordionist, as told to Zello Cassolino, fourth edition (Harrington Arts Center Publication, Superior, Wisconsin: 2002) Another great popular American accordionist was Dick Contino, who toured with the Horace Heidt Orchestra and was billed as the "world's greatest accordion player." He appeared on The Ed Sullivan Show a record 48 times.Bob Bove with Lou Angellotti, Accordion Man: The Legendary Dick Contino (Father and Son Publishing, Tallahassee, Florida: 1994) In addition, John Serry, Sr. achieved national recognition on tour with Shep Fields and His Rippling Rhythm jazz orchestra during the 1930s, concertized on the CBS radio and television networks in the 1940s and 1950sEastman School of Music - University of Rochester - Sibley Music Library: John J. Serry Sr. Collection Photograph of John Serry accordionist on CBS' C de Las A program circa 1940s p. 3, Series 3, Collection Box 3, Item 1: The John J. Serry Sr. Collection archived at the University of Rochester Eastman School of Music and appeared in the Broadway Theatre during the 1950s and 1960s.The Los Angeles Examiner, October 9, 1938, Pg. 1"Discography of American Historical Recordings" - John Serry's performances in recordings with the Shep Fields Orchestra on adp.library.ucsb.edu"Celebrating National Music Week - Accordion Concert" : John Serry - p. 12...appearing with award winner Shirly Booth in "Time of the Cuckoo" See photograph and caption of John Serry in the "Reading Eagle" April 19, 1953 p. 12 on Google BooksNew York Journal-American (see the photograph of Serry's signature inscribed with signatures of other members of the cast on the stage door of the Empire Theatre at the closing of the play The Time of the Cuckoo), May 25, 1953, p. 15

During the 1950s through the 1980s the accordion received great exposure on television with performances by Myron Floren—the accordionist with Lawrence Welk—on the Lawrence Welk Show.Myron Floren and Randee Floren, Accordion Man, with a foreword by Lawrence Welk (The Stephen Greene Press, Brattleboro, Vermont: 1981) However, with the advent of rock 'n roll and the generation gap in the late 1950s and early 1960s, the accordion declined in popularity, as the younger generation considered it "square"— epitomizing the light-hearted music of their parents and grandparents.Henry Doktorski, The Classical Squeezebox: A Short History of the Accordion and Other Free-Reed Instruments in Classical Music, The Classical Free-Reed, Inc. (2005), 125. In the United States, it has often been thought of as a "European instrument," despite the accordion having a presence in American music ever since its creation. Because of this, the accordion has often been the subject of "dumb Euro" stereotypes (portraying Central and Eastern European people as goofy or unintelligent), although modern performers are working to change that stereotype.

In Europe and North American (outside of Mexico), in contemporary mainstream pop music, the use of the accordion is usually considered exotic or old-fashioned. Nevertheless, some popular acts do use the instrument in their distinctive sounds, and a 2014 Los Angeles Times article reports that the instrument is growing in popularity locally. (See the list of popular music acts that incorporate the accordion.) Since the late 19th century, Tejano music has emerged as one of the leading genres for the instrument in America. Pioneers such as Narciso Martínez gave the instrument staple in the cultural music of Mexican American people. Central to the evolution of early Tejano music was the blend of traditional forms such as the Corrido and Mariachi, and Continental European styles, such as Polka, introduced by German and Czech settlers in the late 19th century. In particular, the accordion was adopted by Tejano folk musicians at the turn of the 20th century, and it became a popular instrument for amateur musicians in Texas and Northern Mexico.

The accordion is popular among folk punk and folk rock bands who perform music from countries that often use the accordion, such as in the subgenres of celtic punk and gypsy punk. Such bands include The Dreadnoughts, Gogol Bordello, the Zydepunks, and Flogging Molly.