Joshua Ralph (born 1974/75) , better known as J. Ralph, is a musician whose songs have been featured in modern commercial advertisements for companies including Porsche, Nike, Volkswagen and Volvo.

Never having undergone any formal musical training, he is unable to read or write music[citation needed]. However, he is well-known for being able to play a variety of instruments quickly. These include but are not limited to, the oboe, the saxophone, the triangle, the harp and the kazoo. This ability has allowed him to create polyphonic compositions, including recording with a 56-piece orchestra mostly consisting of members of the New York Philharmonic Symphony, most notably in his piece entitled "Untitled 17". He has recorded two CDs: The Illusionary Movements of Geraldine and Nazu and Music to Mauzner By, the latter under the moniker "Spy". In 1999, his song "Won't You Come Down" was included on the soundtrack for the film Mystery Men. It was attributed to his moniker, "SPY."

Ralph composed the score to the Hollywood production Lucky Number Slevin. His recording studio is located in a former silent-movie theater in Manhattan.

On November 8, 2008 the world premiere of his Fanfare for the Uncommon Ellie and Mr. Greene was performed by the Promusica Chamber Orchestra at the South Theatre in Columbus, Ohio.