Hearts of Soul was formed by three Dutch Indo sisters from Harderwijk: Bianca, Stella and Patricia Maessen (1952-1996). They later moved to Veghel, also in the Netherlands.
They worked in the late 1960s as session singers for Dusty Springfield until 1968. In 1969, they recorded their debut album. In 1970, they sung Waterman (written by Pieter Goemans) as the Netherlands entry to the Eurovision Song Contest. They finished 7th out of 12 participants. Their single It's Great Fun was arguably their most popular at the time. They collaborated in 1972 on a single with Marius Monkau. The song Oh Complete Jesus is still popular, especially amongst religious people.
In the mid-seventies the group moved to Belgium. There they formed Dream Express in 1975 with former Pebbles musician Luc Smets (who married Bianca). In the summer of 1976 they had a Flemish number 2 hit with the self-titled song Dream Express. On 5 February 1977 they won the national finals in Belgium to enter the Eurovision Song Contest 1977, which was held in Wembley, London on Saturday 7 May. This was the first time that Belgium had entered a song to be sung in English. With the song A Million in One, Two, Three they reached 7th place out of 18 participating countries.