As a rule, group efforts are normally launched before a solo career -- not after a solo career is in full swing.
First, the artist makes a name for himself/herself as part of a group, then the artist leaves the group to become a full-time solo performer. That's the standard procedure, but British singer/songwriter Imogen Heap took a different approach, having already established her solo credentials for several years before becoming half of the London-based duo Frou Frou. Although based in London, Heap was raised in Essex, England, where she first studied European classical piano. While attending boarding school years later, a teenaged Heap discovered alternative pop/rock, Euro-pop, and electronica, a musical mixture that effectively ended her previous desire to become a classical instrumentalist. With her focus now devoted to popular music, she signed with Almo Sounds in 1997, becoming a professional solo artist while still in her late teens.
I Megaphone, Imogen Heap's debut album, was released by Almo in 1998, featuring influences that ranged from Kate Bush (to whom she was frequently compared) to Annie Lennox to Björk. Although some tracks were self-produced, I Megaphone also found Heap working with three different producers -- David Kahne, Dave Stewart (of Eurythmics' fame), and Guy Sigsworth -- the latter of whom kept in touch with Heap after the album's release. In the early 2000s, Sigsworth and Heap worked together once again, this time sharing equal responsibilities in the collaborative project Frou Frou. Despite the duo's lighthearted name, Frou Frou utilized electronics to create an atmospheric, dreamy, and nuanced sound. MCA/Universal signed the group in 2001, thus putting Heap's solo career on temporary hiatus.
Frou Frou released Details in 2002, with "Breath In" serving as the album's first single. Two years later, a wider audience discovered Frou Frou's music when "Let Go" was included in the award-winning Garden State soundtrack. Frou Frou had already disbanded by this point, however, and Heap had begun returning her focus to her solo career. She released Speak for Yourself in 2005, gaining notice for such singles as "Hide & Seek" (an a cappella song that utilized a digital harmonizer) and "Goodnight and Go." Ellipse, her third studio album, which she recorded in locations including Japan, Thailand, China, and her home studio, appeared in 2009. The success of the record led to Heap taking home the Grammy Award for Best Engineered Album (Non-Classical) the following year.
Work began on her fourth album began in 2011 when she requested her fans send her "sound seeds," which included samples of every day sounds, that Heap repurposed to create the single "Lifeline." Many other projects followed and Heap continued to explore the uses of new technologies; "Propeller Seeds" explored the use of 3-D audio effects. A total of 13 tracks were released over a three-year period, and were collated for her fourth album, Sparks, which appeared in the summer of 2014. ~ Alex Henderson, Rovi