For himself, he wrote eight U.S. Top Ten pop hits, including the chart-toppers "Breaking Up Is Hard to Do," "Laughter in the Rain," and "Bad Blood." The most successful cover of one of his compositions was Captain & Tennille's recording of "Love Will Keep Us Together," another number one.

 Over the years his songs were recorded by a wide range of pop, rock, country, R&B, and jazz performers including ABBA, Frankie Avalon, LaVern Baker, Shirley Bassey, Teresa Brewer, Carol Burnett, Glen Campbell, the Carpenters, Nick Carter, David Cassidy, Cher, Petula Clark, Richard Clayderman, Patsy Cline, Rosemary Clooney, Sheryl Crow, Vic Damone, Bobby Darin, John Davidson, Neil Diamond, Gloria Estefan, the 5th Dimension, the Four Seasons, Connie Francis, Crystal Gayle, Lesley Gore, the Happenings, Engelbert Humperdinck, Wanda Jackson, Jan & Dean, Tom Jones, Carole King, Earl Klugh, Peggy Lee, Little Anthony & the Imperials, Tony Martin, Johnny Mathis, Susannah McCorkle, Clyde McPhatter, Mandy Moore, Nana Mouskouri, Maria Muldaur, the Monkees, Jim Nabors, Wayne Newton, Jane Olivor, Donny Osmond, Patti Page, the Partridge Family, Bernadette Peters, Wilson Pickett, Elvis Presley, Cliff Richard, the Searchers, Sha Na Na, Kay Starr, John Travolta, Dinah Washington, Andy Williams, and Glenn Yarbrough, among many others. *

* from AllMusic by William Ruhlmann