Clare grew up in Kenya before moving to Manchester to attend Chethams School of Music, where she trained as a classical violinist and also studied classical voice. During this time she met bassist Steve Berry of Loose Tubes, and started getting into jazz. She followed on to Guildhall School of Music and Drama in London to study composition and voice on the jazz course under Lee Gibson, Pete Churchill and Tim Garland, as well as classical singing with Penny Mackay.

Clare freelanced in London as a jazz singer, composer, and arranger, and taught Music Theory and Harmony at the Academy of Contemporary Music, before joining the internationally renowned Swingle Singers in the summer of 2007. Although the group takes her abroad for much of the year, she still writes prolifically for her own ensembles.