A Sheffield festival which brings communities together by celebrating international culture is to welcome its ‘best lineup ever’ this year. Tickets for the city’s ninth Migration Matters Festival - which is the UK’s biggest Refugee Week event and attracted 13,400 people last year - have gone on sale. Headliners for the nine-day arts festival in June include Grammy- nominated husband-and-wife musical duo, Amadou & Mariam, who performed their Afrobeat hits at Glastonbury last year.