Two world-class artists, Elvis Costello and Angelique Kidjo, join Patti Smith, Gruff Rhys, Passenger and Billy Bragg as headline music acts at this year’s Festival of Voice (7-17 June, across Cardiff). Elvis Costello & The Imposters will close this year’s 11-day festival at Wales Millennium Centre, with the skilled wordsmith and unique vocalist covering everything from politics to love songs. Beninese vocalist and activist, Angélique Kidjo, performs her latest project, a reinterpretation of the classic Talking Heads album ‘Remain in Light’. Well-known…