Although Emma Hewitt had a musical background in rock music, she released her debut single in 2007 in the field of progressive house. "Carry Me Away" was a collaboration with British DJ Chris Lake. The single reached number 11 in the Spanish singles charts as well as number 12 in Finland. The single spent a total of 50 weeks in the Billboard Hot Dance Airplay charts in the United States and reached number 1 in December 2007.

Hewitt was the lead singer of the Australian rock band Missing Hours, with whom she released the eponymous debut album in October 2008 through Sony Australia. The band that she formed with her brother Anthony is currently no longer active, because both now live in Los Angeles and are now working as songwriters of electronic dance music.

After the success of her first single, she has worked with several trance artists such as Armin van Buuren, Dash Berlin, Cosmic Gate, Gareth Emery, Serge Devant and BT. The single "Waiting", which she published with Dash Berlin in 2009, was ranked 25th in the Belgian singles chart and No. 1 on the Global Trance Charts. In Armin van Buuren's popular radio show A State of Trance the single was elected by the audience with 2109 votes to the second best song of the year 2009. At the International Dance Music Awards 2010 "Waiting" was awarded as best HiNRG/Euro Track. She was nominated twice in the category Best Trance Track with "Waiting" and "Not Enough Time".