"Hard" is a song by Barbadian recording artist Rihanna from her fourth studio album, Rated R, which was released in 2009. The song was written by Terius Nash, Christopher Stewart, Rihanna, and Jeezy, with vocals performed by the latter two. Nash and Stewart produced it under their stage names, The-Dream and Tricky Stewart. "Hard" was released by Def Jam Recordings on February 19, 2010, as the second United States single from Rated R. It is a hip hop song and features military horns, hissing synthesizers, sharp beats and piano chords. Critics commended "Hard" for Rihanna's vocal performance and Jeezy's collaboration.

The song became Rihanna's thirteenth top ten hit on the US Billboard Hot 100, matching Beyoncé Knowles as the female artist with the most US top ten songs since 2000. It was certified platinum by the Recording Industry Association of America. An accompanying music video, directed by Melina Matsoukas, was filmed in Los Angeles in December 2009. In the video, Rihanna commands an army while clothed in stylized military costumes. Critics praised the video and noted a difference from her previous clips. After the video premiere, the song charted in Canada, New Zealand and the United Kingdom. Rihanna performed "Hard" at Jay-Z's concert at UCLA Pauley Pavilion and at the 2009 American Music Awards. The song was also included on the set lists of the Last Girl on Earth Tour (2010–11) and the Loud Tour (2011).

Hard or Hardness may refer to:

In music, a song is a composition for voice or voices, performed by singing. A song may be accompanied by musical instruments, or it may be unaccompanied, as in the case of a cappella songs. The lyrics (words) of songs are typically of a poetic, rhyming nature, though they may be religious verses or free prose.

A song may be for a solo singer, a duet, trio, or larger ensemble involving more voices. Songs with more than one voice to a part are considered choral works. Songs can be broadly divided into many different forms, depending on the criteria used. One division is between "art songs", "pop songs", and "folk songs". Other common methods of classification are by purpose (sacred vs secular), by style (dance, ballad, Lied, etc.), or by time of origin (Renaissance, Contemporary, etc.).

A song is a piece of music for accompanied or unaccompanied voice or voices or, "the act or art of singing," but the term is generally not used for large vocal forms including opera and oratorio. However, the term is, "often found in various figurative and transferred sense (e.g. for the lyrical second subject of a sonata...)." The noun "song" has the same etymological root as the verb "to sing" and the Oxford English Dictionary (OED) defines the word to mean "that which is sung" or "a musical composition suggestive of song." The OED also defines the word to mean "a poem" or "the musical phrases uttered by some birds, whales, and insects, typically forming a recognizable and repeated sequence and used chiefly for territorial defence or for attracting mates."

Hard Kaur (born Taran Kaur Dhillon born 29 July 1979), also known as Hardkaur, is an Indian rapper and hip hop singer, as well as playback singer in Hindi films; she is the first female Indian rapper. She was kicked out of a college performance for shameful unprofessionalism.

She was born Taran Kaur Dhillon in Meerut, Uttar Pradesh, where her mother ran a small beauty parlour in the house. When she was young, her father was burnt alive during 1984 Anti-Sikh riots and her mother's beauty parlour was burnt a few days after her father's death. Her paternal grandparents asked her mother to leave their house and wanted to keep only Taran and her brother with them. Subsequently she, her brother and her mother moved to Ludhiana to her maternal grandparents house, where they stayed for the next couple of years.

In 1991 her mother remarried an NRI and her family moved to Birmingham, England, where her mother started working and studying to eventually open a beauty salon. Meanwhile she did her schooling. After developing interest in hip-hop she started her musical career as a rapper.

Lily Rose Beatrice Cooper (born 2 May 1985), better known as Lily Allen, is an English recording artist, actress and fashion designer. She is the daughter of actor and musician Keith Allen and film producer Alison Owen. In her teenage years, her musical tastes evolved from glam rock to alternative. Allen abandoned school and concentrated on improving her performing and compositional skills. Afterwards, she created several demo songs and, near the end of 2005, she created a profile on MySpace where she made some of her recordings public.

A contract was signed with the label Regal Recordings, as the views on MySpace rose to tens of thousands. In 2006, she began to work on completing what would be her first studio album and its first mainstream single "Smile" reached the top position on the UK Singles Chart in July 2006. Her debut record, Alright, Still, was well received on the international market, selling over 2.6 million copies and brought Allen a nomination at the Grammy Awards, BRIT Awards and MTV Video Music Awards. She then began hosting her own talk-show, Lily Allen and Friends, on BBC Three.