Musicians don't just look to other musicians for ideas, a song can come from anywhere. To spark creative ideas, it can be useful to take a look at other mediums - novels, poems, plays and paintings - and the life and works of the people who make them.
Here are six BBC programmes about six very different artists whose work has had a direct influence on music, popping up either in specific songs or lyrics, or setting a tone or lyrical theme for the musicians to work within.
1. Frida Kahlo
The dreamlike magical reality of Frida Kahlo's self-portraits came as a way of representing the brutal reality of her life, both in the physical limitations of her body - she had been affected by polio, and started painting after a bus crash left her seriously injured - and the political realities of post-revolutionary Mexico. BBC Radio 4's In Our Time describes the intense focus she developed: "She was so powerful and so self-confident it's almost as if it didn't matter if she had exhibitions. [She'd continue working, as if saying] 'I am going to paint, this is what I do.'"
Madonna is a huge fan, as is Florence Welch, who named her song What the Water Gave Me after a Kahlo painting, and told the Las Vegas Sun: "I love her style, and I think she captured so much strength and fragility in her portraits and the quandary of being feminine and mixing up these ideas of masculine and feminine and the real and the unreal and the pain. She was an amazing artist." Similarly, Chris Martin was inspired to name Coldplay's album Viva la Vida by her painting of the same name, depicting bright watermelons. He told Rolling Stone: "She went through a lot of pain, of course, and then she started a big painting in her house that said Viva la Vida; I just loved the boldness of it."
2. William Burroughs
Because of his friendship with novelist Jack Kerouac, poet Allen Ginsberg and others, William Burroughs is termed a Beat Generation writer, but he's the oddity in the group - older, stylistically different and more satirical. The 'cut-up technique' he created with Brion Gysin - a kind of literary sampling - became hugely influential on other artforms, especially music. Radiohead, David Bowie and many others have employed variations on the technique when making music.
You'd be hard pressed to find any generation of musicians which hasn't taken inspiration from Burroughs. Paul McCartney is a life-long fan; The Velvet Underground song Lonesome Cowboy Bill is about him; Patti Smith once called his work the "new bible"; Joy Division took the word 'Interzone' from a Burroughs collection; Duran Duran's Wild Boys is based on one of his stories; and Kurt Cobain collaborated with him on 1993 spoken word album The "Priest" They Called Him.
Above, performance artist and singer Laurie Anderson profiles Burroughs, her friend.
3. Langston Hughes
Among his many literary achievements in the early 20th century, Langston Hughes was the first African-American to make his living as a poet, working his way into the mainstream of American literature. This has proven to be a direct modern influence on many rappers, with shoutouts from Busta Rhymes (I.C. Y'all), The Roots (Rock You), Common (The Believer) and Rick Ross (Family Ties). Nas referred to himself as both "Langston Hughes's predecessor" (Everybody's Crazy) and "the rebirth of Langston Hughes" (Don't Body Ya Self), cementing his reputation as a cultural touchstone for forward-thinking rhymers.
This Radio 3 documentary explores how Hughes came to work with a BBC producer called Geoffrey Bridson in 1964, on a visionary documentary series on African-American life, called The Negro in America.
4. J. G. Ballard
"Since the early-60s he's been well-known as an author who likes to dwell on the violent and horrific consequences of unpredictable events," presenter Sue Lawley begins this 1992 episode of Radio 4's Desert Island Discs, before pointing out that J. G. Ballard then had huge success with autobiographical novels, including Empire of the Sun. "I'm interested in the next five minutes, I'm interested in change," he says, as many musicians are. His visions of the just-ahead, often very dystopian, proved massively influential on pop, particularly in the post-punk and early electronic music era. Joy Division, Gary Numan and Cabaret Voltaire were all inspired by his writing, so was producer Trevor Horn, and his impact is still being felt in the 21st century. Klaxons, for example, named their debut album, Myths of the Near Future, after a Ballard short story collection.
5. Sylvia Plath
While Plath's influence has extended far beyond that of a cult by now, in her lifetime her poetry was relatively unheralded. Since her death in 1963, interest in her work has blossomed, and with it, musical responses and interpretations. She was namechecked by Lada Gaga in Dance in the Dark, Little Boots wrote Mathematics partly based on lines from her Love Is A Parallax, and she is the subject of songs by Ralph McTell (Sylvia), Ryan Adams (Sylvia Plath) and Paul Westerberg (Crackle and Drag). In 2013, Kathryn Williams wrote an album - Hypoxia - based on her work, to coincide with the 50th anniversary of her death. In this Radio 4 documentary she explains how it was a recording of Plath's carefree laughter that inspired her to look behind the fearsome reputation of the doomed poet.
6. Alan Moore
Correct, that's a picture of comedian Stewart Lee above, but hit play and you'll hear him interview comic book writer Alan Moore (who, in the next episode, interviews Brian Eno). Moore got his break in the music press - his first paid work was doing comics for NME - before going on to create the landmark 1980s graphic novels Watchmen (with Dave Gibbons) and V for Vendetta (with David Lloyd). The influence of those two works in particular across wider culture is enormous - the Guy Fawkes mask worn in V for Vendetta, for example, was adopted by Occupy protesters earlier this decade - and Moore's impact on music is just as considerable. "Alan Moore knows the score," sang Pop Will Eat Itself on 1989 song Can U Dig It?, David J of Bauhaus released a four-track EP based on V for Vendetta, and the Transvision Vamp song Hanging Out with Halo Jones is an ode to Moore's strip for 2000 AD, The Ballad of Halo Jones.
Moore also frequently collaborates with musicians, including David J (they briefly had a band together called The Sinister Ducks), Stephen O'Malley of doom rock group Sunn O))), and Crook&Flail, a production duo consisting of Andrew Broder of Fog and Doseone, who wrote a score for his 2010 essay Unearthing.