According to the Great American Songbook Foundation:

The "Great American Songbook" is the canon of the most important and influential American popular songs and jazz standards from the early 20th century that have stood the test of time in their life and legacy. Often referred to as "American Standards", the songs published during the Golden Age of this genre include those popular and enduring tunes from the 1920s to the 1950s that were created for Broadway theatre, musical theatre, and Hollywood musical film.

Culture writer Martin Chilton defines the term "Great American Songbook" as follows: "Tunes of Broadway musical theatre, Hollywood movie musicals and Tin Pan Alley (the hub of songwriting that was the music publishers' row on New York's West 28th Street)". Chilton adds that these songs "became the core repertoire of jazz musicians" during the period that "stretched roughly from 1920 to 1960".

Although several collections of music have been published under the "Great American Songbook" title, the term does not refer to any actual book or specific list of songs. The Great American Songbook includes standards by Irving Berlin, George Gershwin, Cole Porter, Jerome Kern, Harold Arlen, Johnny Mercer, Hoagy Carmichael, Richard Rodgers, and Oscar Hammerstein II, among others.

In Alec Wilder's 1972 study, American Popular Song: The Great Innovators, 1900–1950, the songwriter and critic lists and ranks the artists he believes belong to the Great American Songbook canon. A composer, Wilder emphasized analysis of composers and their creative efforts in this work.

Radio personality Jonathan Schwartz and singer Tony Bennett, both Songbook devotees, have both described this genre as "America's classical music".

In 1970, rock musician Ringo Starr surprised the public by releasing an album of Songbook songs from the 1920s, 1930s, and 1940s, Sentimental Journey. Reviews were mostly poor or even disdainful, but the album reached number 22 on the US Billboard 200 and number 7 in the UK Albums Chart, with sales of 500,000.

It's a lot of songs that were my initiation to music. It's all the tracks that, when my mother and my father came home from the pub out [of] their heads, they'd sing all these songs.

— Ringo Starr

Other pop singers who established themselves in the 1960s or later followed with albums reviving songs from the Great American Songbook, beginning with Harry Nilsson's A Little Touch of Schmilsson in the Night in 1973 and continuing into the 21st century. Linda Ronstadt (1983 though 1986), Rod Stewart (2002 through 2005), Bob Dylan (2015 through 2017) and Lady Gaga (2014 and 2021) made several such albums. Of Ronstadt's 1983 album, What's New, her first in a trilogy of standards albums recorded with arranger/conductor Nelson Riddle, Stephen Holden of The New York Times wrote:

What's New isn't the first album by a rock singer to pay tribute to the golden age of pop, but is ... the best and most serious attempt to rehabilitate an idea of pop that Beatlemania and the mass marketing of rock LPs for teen-agers undid in the mid-'60s. During the decade prior to Beatlemania, most of the great band singers and crooners of the '40s and '50s codified a half-century of American pop standards on dozens of albums, many of them now long out-of-print.

• Great American Songbook Foundation
• Lounge music
• Show tunes
• Tin Pan Alley
• Traditional pop

• Bloom, Ken (2005). The American Songbook: The Singers, the Songwriters, and the Songs. New York: Black Dog & Levental Publishers. ISBN 1-579-12448-8.
• Furia, Philip (1992). Poets of Tin Pan Alley. New York & Oxford: Oxford University Press. ISBN 0-195-07473-4.
• Furia, Philip (2006). (with Michael Lasser) America's Songs: The Stories Behind the Songs of Broadway, Hollywood, and Tin Pan Alley. Routledge. ISBN 0415990521.
• Furia, Philip (2010). (with Laurie Patterson) The Songs of Hollywood. New York & Oxford: Oxford University Press. ISBN 978-0195337082.
• Furia, Philip (2015). (with Laurie Patterson) The American Song Book: The Tin Pan Alley Era. New York & Oxford: Oxford University Press. ISBN 978-0199391882.
• Morath, Max (2002). The NPR Curious Listener's Guide to Popular Standards. Penguin-Perigee Trade. ISBN 978-0-399-52744-9.
• Yagoda, Ben (2015). The B-Side: The Death of Tin Pan Alley and the Rebirth of the Great American Song. New York: Riverhead Books. ISBN 978-1-594-48849-8.
• Zinsser, William (2001). Easy to Remember: The Great American Songwriters and Their Songs. Boston: David R. Godine. ISBN 1-567-92147-7.

• Martini in the Morning radio program featuring the Great American Songbook
• PBS Special on the Great American Songbook
• Popular Songwriters and The Great American Songbook
• The American Songbook Preservation Society
• The Great American Songbook Foundation
• The Society for the Preservation of the Great American Songbook