Dermot O'Leary presents another Saturday night live show as the UK's biggest singing competition reaches the quarter-final stage. With only two live shows left before the final, the remaining contestants will be feeling the pressure to deliver their best performances yet. As witnessed last weekend with the departure of bookies' favourite Ella Henderson, no act is safe from elimination. Tonight's themes are Motown and Abba, so the acts will each get to perform two songs from an extensive back catalogue of choices. In such an unpredictable year, which performances will fail to impress the public this week?
