Dennis achieved her number one profits as a singer using a dance class action D Mob when their single "C'mon and Get My Love" reached a top X in the United Kingdom and United States in 1989.

She scored ternary solo top Twenty U.K/ top X The states hits in the early xc by using "Just Another Dream", "Touch Me (All Night Long)", which is probably her virtually all remembered hit up to now, & "Too Many Walls", however her subsequent releases failed to achieve this level of profits. Her previous Top 40 hit was "Waterloo Sunset" which mass produced #11 in the UK in the period of 1997.

Inside recent years, her greatest profits has came as a ballad maker: 5 of her compositions develop reached first inside Britain. "Never Had a Dream Come True" & "Have You Ever" (two recorded by S Club 7, and a previous of which wwhen when large around America as it was inside Britain), "Anything Is Possible" (recorded by Will Young), and "Toxic" (recorded by Britney Spears) all reached first, sustaining "Toxic" achieving a equivalent deed in the United States. Her greatest-selling composition, "Can't Get You out of My Head" (recorded by Kylie Minogue), spent four weeks at number one in Britain, rekindled interest in Minogue in America, where it hit #7 on the Hot 100, and sold over 3 million copies worldwide to become the world's second highest selling single in 2001. "Can't Get You Out of My Head" besides won Dennis an Ivor Novello Award for the year's virtually all performed composition. She likewise won this award deuce years late for "Anything Is Possible".

She co-wrote a American Idol theme for the television series, & within Britain and a United States contestants Will Young, Gareth Gates, Kelly Clarkson, and Clay Aiken have recorded her songs as their number 1 singles. More creative person world health organization own recorded her songs include Dannii Minogue, Delta Goodrem, Céline Dion, Spice Girls, Emma Bunton, Ronan Keating, Rachel Stevens, Hear'Say, S Club Juniors, Michelle McManus and Jentina.