In jazz and blues, a blue note (also "worried" note) is a note sung or played at a slightly lower pitch than that of the major scale for expressive purposes. Typically the alteration is a semitone or less, but this varies among performers and genres. Country blues, in particular, features wide variations from the diatonic pitches with emotive blue-notes. Blue notes are often seen as akin to relative pitches found in traditional African work songs.

The blue notes are usually said to be the flattened third, flattened fifth, and flattened seventh scale degrees. Though the blues scale has "an inherent minor tonality, it is commonly 'forced' over major-key chord changes, resulting in a distinctively dissonant conflict of tonalities". A similar conflict occurs between the notes of the minor scale and the minor blues scale, as heard in songs such as "Why Don't You Do Right?."

In the case of the flattened third over the root (or the flattened seventh over the dominant), the resulting chord is a neutral mixed third chord.

Dwayne Michael Carter, Jr. (born September 27, 1982), better known by his stage name Lil Wayne, is an American rapper. At the age of nine, Lil Wayne joined Cash Money Records as the youngest member of the label, and half of the duo, The B.G.'z, with B.G.. In 1997, Lil Wayne joined the group Hot Boys, which also included rappers Juvenile, B.G., and Young Turk. Hot Boys debuted with Get It How U Live! that year. Lil Wayne gained most of his success with the group's major selling album Guerrilla Warfare, released in 1999. Also in 1999, Lil Wayne released his Platinum debut album Tha Block Is Hot, selling over one million copies in the U.S.

Although his next two albums Lights Out (2000) and 500 Degreez (2002) were not as successful (only reaching Gold status), Lil Wayne reached higher popularity in 2004 with Tha Carter, which included the single "Go D.J." Wayne also appeared on the Destiny's Child top ten single "Soldier" that year. In 2005, the sequel to Tha Carter, Tha Carter II, was released. In 2006 and 2007, Lil Wayne released several mixtapes and appeared on several popular rap and R&B singles. His most successful album, Tha Carter III, was released in 2008 and sold over 1 million copies in the U.S. its first week of release. It included the number-one single "Lollipop" featuring Static Major. It also includes the singles "A Milli" and "Got Money" featuring T-Pain and won the Grammy Award for Best Rap Album.

Toby Keith Covel (born July 8, 1961) best known as Toby Keith, is an American country music singer-songwriter, record producer and actor. Keith released his first four studio albums — 1993's Toby Keith, 1994's Boomtown, 1996's Blue Moon and 1997's Dream Walkin', plus a Greatest Hits package for various divisions of Mercury Records before leaving Mercury in 1998. These albums all earned gold or higher certification, and produced several chart singles, including his debut "Should've Been a Cowboy", which topped the country charts and was the most played country song of the 1990s. The song has received three million spins since then, according to Broadcast Music Incorporated.

Signed to Nashville DreamWorks in 1998, Keith released his breakthrough single "How Do You Like Me Now?!" that year. This song, the title track to his 1999 album of the same name, was the Number One country song of 2000, and one of several chart-toppers during his tenure on DreamWorks Nashville. His next three albums, Pull My Chain, Unleashed, and Shock'n Y'all, produced three more Number Ones each, and all of the albums were certified multi-platinum. A second Greatest Hits package followed in 2004, and after that, he released Honkytonk University.