The deaths of Jerry Leiber and Nick Ashford this week ended the careers of two of the most prolific and influential songwriting duos. With Mike Stoller, Leiber wrote many of rock and roll's earliest hits, including "Hound Dog," "Stand By Me" and "Smokey Joe's Café." As the husband and partner of Valerie Simpson, Ashford co-wrote countless songs for Motown, penning tracks for Marvin Gaye, The Supremes and Smokey Robinson & the Miracles. The duo later earned widespread renown with the 1984 soul ballad "Solid." Billboard.com looks back at 10 other classic songwriting duos that changed the shape of music.

Richard Rodgers & Oscar Hammerstein II
Classic songs: "The Sound of Music," "Some Enchanted Evening," "Oklahoma"

No duo was more successful and ubiquitous in the pre-rock and roll era than composer Richard Rodgers and lyricist Oscar Hammerstein II. The pair was responsible for such enduring musicals as "South Pacific," "Oklahoma!" and "The Sound of Music," garnering nearly 35 Tony Awards and 15 Academy Awards. While still retaining an overall cheerfulness, Rodgers and Hammerstein imbued musical theatre with poignant, thoughtful plots that pushed the medium in unprecedented directions.

Daryl Hall & John Oates
Classic songs: "Rich Girl," "Private Eyes," "I Can't Go For That (No Can Do)"

Despite long-standing critical drubbing dismissing the Philly duo as watered-down soul, no other duo dominated the 1980s so consistently, with five albums from 1980-1988 all going platinum (at least). Daryl Hall and John Oates would eventually land 34 singles on the Hot 100 and be ranked #15 on Billboard's Hot 100 All-Time Top Artists. In the late 80s and 90s, the duo found a second career as sampling material for everyone from Kanye West to De La Soul.

Morrissey & Johnny Marr
Classic songs: "This Charming Man," "Hand in Glove," How Soon Is Now?"

The quintessential UK mope-pop band of the 1980s was always a cult act stateside - "How Soon Is Now?," their highest-charting song, only reached #36 on the U.S. Dance chart - but lead singer Morrissey and guitarist Johnny Marr fused catchy, jangly guitar riffs with Morrissey's reflective, cynical lyrics that would influence a generation of bands. Every decade or so, a new crop of teenagers discovers The Smiths and wonders how Morrissey could reflect back their growing sense of malaise, ennui and despair so perfectly.

Kenny Gamble & Leon Huff
Classic songs: "If You Don't Know Me By Now," "Love Train" "The Love I Lost"

A protégé of Ashford & Simpson, Hall of Fame members Kenny Gamble and Leon Huff helped define soul music in the 1970s, augmenting soul tracks with lush, sweeping strings and more prominent bass lines. The duo's Philadelphia International label, which included The O'Jays, Harold Melvin & the Blue Notes and soul collective MFSB, would rival Motown as the nation's pre-eminent soul label and influence both disco and Quiet Storm.

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