Nickname for the popular songwriting and sheet-music publishing industry centred in New York from the 1890s to the 1950s. By association it came to be applied to the general type of song purveyed by the industry both in America and then Europe up until the rise of the singer-songwriter in the mid-1960s. Suggesting the tinny sound of the overworked upright pianos used by song pluggers in publishers' salerooms, the term is said to have been coined by Monroe H. Rosenfeld, composer of such songs as Those wedding bells shall not ring out (1896), Take back your gold (1897) and She was happy till she met you (1899). Founding firms of Tin Pan Alley included H. Witmark & Sons (the largest company), T.B. Harms & Co., Hawley, Haviland & Co., Joseph W. Stern & Co., Feist & Frankenthaler and F.A. Mills. Originally at East 14th Street and around Union Square, the location of the ‘alley’ shifted with music publishers to around West 28th Street in the 1890s, the period when the term itself became common. Tin Pan Alley's equivalent centre in London was Denmark Street, off Tottenham Court Road. The centre of activity shifted in New York between the World Wars to Broadway, around 50th Street, and particularly became associated with the Brill Building, with such songwriters as Gerry Goffin and Carole King at Aldon Music, Leiber and Stoller, and Jeff Barry and Ellie Greenwich at Trio Music.
Definition taken from: H. Wiley Hitchcockr, 'Tin Pan Alley', Grove Music Online ed. L. Macy (Accessed [Wednesday, November 28, 2007]) http://www.grovemusic.com.