"Por una Cabeza" is an Argentine tango with music and lyrics written in 1935 by Carlos Gardel and Alfredo Le Pera respectively.
The name is a Spanish horse-racing phrase meaning "by a head", which refers to a horse winning a race by the length of one head. The lyrics speak of a compulsive horse-track gambler who compares his addiction for horses with his attraction to women.
Alfredo Le Pera was a Brazilian from São Paulo, a much Italian-influenced area in Brazil, and also the birthplace of Zequinha de Abreu, composer of Tico-Tico no Fubá. Le Pera and Gardel died in an airplane crash in Medellín, (Colombia), on June 24, 1935.
The tango has since been performed by numerous tango orchestras. Tango scenes with "Por una Cabeza" appear in Delicatessen (1991), Scent of a Woman (1992), Schindler's List (1993), True Lies (1994), Titanic (1996), Bad Santa (Uncut Version, 2003), All the King's Men (2006), Planet 51 (2009), episode 37 of Nip/Tuck (2003–2010), episode 9 of South Korean drama series Sweet Spy (2005–08), the beginning and ending credits of the South Korean drama broadcast I'm Sorry, I Love You (2004), and the CSI: NY episode "Down the Rabbit Hole" (2007). In the movie Frida (Salma Hayek, 2002), Gardel is heard singing it on a radio. It is also quoted in David Del Tredici's "Good News! Nilda is Back" (from the song cycle Miz Inez Sez). In Scent of a Woman (1992), the tango is performed by the "The Tango Project",consisting of William Schimmel (accordion), Michael Sahl (piano) and Stan Kurtis (violin), who actually appear in the dancing scene starring Al Pacino (the recording used is available on one of their CD albums). John Williams arranged a version of the piece that appears on the album "Cinema Serenade" with the violin solo performed by Itzhak Perlman. Perlman and Williams (conducting) have also performed the piece together in live concerts. In 2012 a dance version was released by the group "Da Carrera" featuring the original vocal recording by Carlos Gardel.