On disc-based video formats, an audio commentary is an additional audio track consisting of a lecture or comments by one or more speakers, that plays in real time with video. Commentaries can be serious or entertaining in nature, and can add information which otherwise would not be disclosed to audience members.^{[dead link]}

The DVD medium allows multiple audio tracks for each video program. DVD players usually allow these to be selected by the viewer from the main menu of the DVD or using the remote. These tracks will contain dialogue and sound of the movie, often with alternative tracks featuring different language dialogue, or various types of audio encoding (such as Dolby Digital, DTS or PCM). Among them may be at least one commentary track.

There are several different types of commentary. The two main types simply define the length of the commentary rather than the type of content. They are:

Typically a commentary track will include feature-length commentary from the film's director, cast members, or occasionally writers and producers. Occasionally actors will perform commentary in-character. (In recording sessions with multiple speakers, a designated moderator may encourage the discussion flow.) Some DVDs include outsider commentary performed by film critics, historians, scholars or fans. In more elaborate productions, multiple speakers from various recording sessions may be edited together for a single audio program.

Jacob Benjamin "Jake" Gyllenhaal ( /ˈdʒɪlənhɔːl/ JIL-ən-hawl; born December 19, 1980) is an American actor. The son of director Stephen Gyllenhaal and screenwriter Naomi Foner, Gyllenhaal began acting at the age of ten. Following his first lead role in 1999's October Sky, he starred in the indie cult hit Donnie Darko (2001), in which he played a psychologically troubled teenager alongside his older sister, actress Maggie Gyllenhaal. In 2004 he appeared in the science-fiction film The Day After Tomorrow, portraying a student caught in a cataclysmic global cooling event. He then played against type as a frustrated Marine in Jarhead (2005). The same year his role as Jack Twist in Brokeback Mountain earned him critical acclaim and an Academy Award nomination for Best Supporting Actor. He has since played the lead roles in many notable films, including Zodiac (2007), Prince of Persia: The Sands of Time (2010) and Source Code (2011).

Gyllenhaal has promoted various political and social causes. He has appeared in Rock the Vote advertising, campaigned for the Democratic Party in the 2004 U.S. presidential election, promoted environmental causes, and campaigned on behalf of the American Civil Liberties Union.

Martin Charles Scorsese ( /skɔrˈsɛsɛ/; born November 17, 1942) is an American film director, screenwriter, producer, actor, and film historian. In 1990 he founded The Film Foundation, a non-profit organization dedicated to film preservation, and in 2007 he founded the World Cinema Foundation. He is a recipient of the AFI Life Achievement Award for his contributions to the cinema, and has won Academy Award, Palme d'Or, Emmys, Golden Globes, BAFTAs, and DGA Awards.

Scorsese's body of work addresses such themes as Italian American identity, Roman Catholic concepts of guilt and redemption,machismo, modern crime, and violence. Scorsese is hailed as one of the most significant and influential filmmakers of all time, directing landmark films such as Mean Streets (1973), Taxi Driver (1976), Raging Bull (1980), and Goodfellas (1990) – all of which he collaborated on with actor and close friend Robert De Niro. He won the Academy Award for Best Director for The Departed (2006), having been nominated a previous five times.