EARLIER today, a US court ruled in favor of singer-songwriter Ed Sheeran, agreeing his song “Thinking Out Loud” did not breach musical copyright.

The high-profile court case, brought by the estate of soul singer Marvin Gaye, claimed Sheeran’s song was too similar to Gaye’s song “Let’s Get It On.”

On the stand, Sheeran defended his songwriting process, stating: “I draw inspiration from a lot from things in my life and family.”

Sheeran’s case brought up some difficult questions around what we understand as inspiration and influence, and what we may hear as theft.

Musical copyright cases are part of songwriting history. Radiohead’s “Creep” was found to be too similar to the Hollies’ “The Air That I Breathe,” and in 2018, Lana Del Rey’s “Get Free” was found to plagiarize “Creep.”

Mark Ronson and Bruno Mars altered the credits to “Uptown Funk” to acknowledge the similarity to The Gap Band’s “Oops Upside Your Head.”

Here in Australia, the flute solo in Men at Work’s “Down Under,” which quoted the melody of folk song “Kookaburra Sits in the Old Gum Tree,” was ruled as plagiarism.

In this case against Sheeran, the song’s chord progression was at the heart of the claim. The prosecution argued Sheeran’s chord progression was too similar to the chord progression of Gaye’s.

But can we copyright a chord progression if it is used extensively in other pop songs?

Gaye’s song uses four chords that gradually move upward (I-iii-IV-V). These same chords can be heard in the Beach Boys’ “I Can Hear Music,” the Seekers’ “Georgy Girl,” the Beatles’ “I Feel Fine,” in the Motown tune “This Old Heart of Mine” by the Isley Brothers, Elvis Presley’s “Suspicious Minds,” Cher’s “Believe,” and ABBA’s “Knowing Me Knowing You,” among many others.

This chord progression and many others are part of the songwriting toolkit of rock and pop and have been heard continuously over the past 70 years.

A chord progression is the main instrumental part you hear in most pop music, usually played by a guitar, piano, or synth.

One of the oldest chord progressions in pop is the 12-bar blues — a looping pattern of three chords that is very identifiable.

As the name suggests, this set of chords stems from early blues and was a way for musicians to easily play together and improvise. A version of this progression can be heard in Muddy Waters’ “I’m Your Hoochie Coochie Man” or John Lee Hooker’s “Boom Boom.”

You can also hear this progression in a number of other pop songs — listen to verses of Queen’s “I Want to Break Free” and “Kiss” by Prince — both use the same chord progression, but sound very different to each other.

More recently, Lizzo’s “Better in Color” uses the 12-bar blues in a way that makes an old formula fresh.

The “doo-wop” progression has appeared in pop music for close to 80 years, and is named because most doo-wop songs feature this chord progression — it was an essential part of its sound.

You can hear it in 1950s hits such as the Penguins’ “Earth Angel” and Frankie Lymon and the Teenagers’ “Why Do Fools Fall in Love?.”

The strength of these chords means they are used in pop music of all kinds, including ELO’s “Telephone Line,” “Don’t Dream it’s Over” by Crowded House, Destiny’s Child’s “Say My Name,” “Blank Space” by Taylor Swift, and “Flowers” by Miley Cyrus.

Despite its consistent use, these chords still cross genres and eras, and still catch our ears.

Comedy act Axis of Awesome use a similar progression in their video for “4 Chords,” where they cleverly play almost 50 different songs with a variation on these four simple chords. (Go to (1) 4 Chords | Music Videos | The Axis Of Awesome – YouTube

Perhaps the most common chord progressions in rock and pop are those that use the I, IV, and V chords in various combinations.

They’re usually the first three chords you learn on an instrument and open up thousands of songs to play — from the rock and roll of “Summertime Blues” by Eddie Cochran, the garage rock of “Wild Thing” by the Troggs, the bubblegum of Hanson’s “Mmmbop ,”and the indie rock of Coldplay’s “Yellow,” to the modern pop of “bad guy” by Billie Eilish and “good 4 u” by Olivia Rodrigo.

Rock, pop, blues, doo wop, and other musical genres can often be defined by their use of repeated chord progressions. These chord progressions are part of a songwriter’s toolkit in a similar way to how an artist may use different paint brushes.

As Sheeran’s lawyer Ilene Farkas noted, chord progressions are “the letters of the alphabet of music […] these are basic musical building blocks that songwriters now and forever must be free to use.”

It is how these “building blocks” are used, and in what combinations, that gives us a great variety of pop songs over many decades. The true craft of great pop music is to take these formulas and turn them into something unique (while simultaneously making it sound easy).

The ruling in Sheeran’s case supports the rights of musical artists to continue to use these progressions as part of a songwriter’s toolkit, and to build from the artists who came before them. It also acknowledges that influence and inspiration from previous works are part of the construction of the pop music we love. — The Conversation via Reuters Connect

Jadey O’Regan is a Lecturer in Contemporary Music at the Sydney Conservatorium of Music. She is co-author of Hooks in Popular Music (2022), University of Sydney.