Zoe Rahman, directing the Guildhall Jazz Ensemble, gets the Guildhall jazz festival off to a flying start tonight. The London conservatoire’s annual festival also features Ian Shaw, guesting with the Guildhall Jazz Singers and Ensemble; saxophonist Tom Challenger; Keith Tippett, Julie Tippetts and Paul Dunmall better known as the Dartington Improvising Trio. Iain Ballamy and the Guildhall Jazz Band are also appearing during this year’s running. Zoe Rahman, above