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 pi...