The exhortation "oh" is the subject of a major lawsuit after Jay Z urged a court to dismiss claims that ripped off a single syllable during the making of his hit 2009 track Run This Town.
The rapper is battling a lawsuit which could have a significant impact on future copyright cases which involve the sampling of other artists' music.
The label TufAmerica claims that Run This Town, featuring Rihanna, uses an unlicensed sample from Hook and Sling - Part 1, a 1969 funk composition by Eddie Bo.
Damages and royalties are being sought for a sample of the single vowel sound "oh" from Hook and Sling, which was used once in Run This Town.
Bo died in 2009 but the litigious TufAmerica has previously sued Kanye West for unauthorised use of a sample from the same song.
Jay Z argues that the sample was too insignificant for TufAmerica to claim sole copyright protection over.
Papers filed by the rap superstar's lawyers claimed: "It is black letter law that words and short phrases are simply not protectable under the Copyright Act.
"Thus, Plaintiff cannot state a claim based on the alleged infringement of a generic lyric such as, 'oh,' or the sound recording thereof, and Plaintiffs claims should be dismissed as a matter of law."
"The alleged copying here of a sound lasting a fraction of a second in Plaintiffs Works is de minimis and thus not actionable."
Jay Z's team cited a similar case that TufAmerica lost last year. The label claimed that The Beastie Boys' albums Licensed to Ill and Paul's Boutique contained an unauthorised sample of the phrase "Now I want y'all to break this down" from the band Trouble Funk.
The sample was judged to be so minimal that it "lacks the requisite originality to be afforded copyright protection". Jay-Z argued that his "oh" is an "objectively less significant sound" than the Trouble Funk phrase.
Hip-hop producers, who have always placed samples of old songs in new contexts, are currently restricted by a 2005 ruling which found that a two-second sample from NWA's 100 Miles and Runnin' infringed upon Funkadelic's Get Off Your Ass and Jam.
The judge ruled that licences must be acquired for the use of similar, fleeting, samples but if Jay Z succeeds in throwing out the Run This Town case, artists will be more confident about incorporating similar samples without having to pay publishing royalties.
Hook and Sling has been raided by a number of hip-hop stars. Elements of the song appear on Kanye West's Good Friday and LL Cool J's Mama Said Knock You Out as well as SexyBack by Justin Timberlake.
Run This Town provoked further controversy this week when CBS pulled the track as the intro music for its Thursday Night Football show.
The song was deemed inappropriate because of a domestic violence scandal involving scandal involving NFL player Ray Rice, given Rihanna's relationship with the singer Chris Brown, who had hit her.
"Y'all are sad for penalizing me for this," Rihanna tweeted.