Barcelona's Cruïlla Festival, celebrating its seventh edition at the Parc del Fòrum, is now one of the city's unmissable summer festivals. An eclectic programme both in term of genres and the origins of the performers fills a weekend with rhythm and music. This opening day has a performance that is an exclusive in Spain this year – Kendrick Lamar presenting the excellent 'To pimp a butterfly' (2015). Also on stage will be British singer, composer and pianist Jamie Cullum, king of jazz-pop that is suitable for all audiences, and who will be performing his latest album, 'Interlude' (2014), a record full of jazz and blues standards. Cruïlla is hosting the first Barcelona concert from Icelandic group Of Monsters and Men, and the experimental pop of the the sister duo CocoRosie will also ring out on the festival's opening day. The rest of the first-day programme includes Capital Cities, another super-hot double act made up of Ryan Merchant and Sebú Simonian, the pair behind 'Safe and sound'; O Rappa, a group that fills stadiums in their native Brasil, and here bring their most recent album 'Nunca tem fim'; the festive, energy-filled carnival that is The Cat Empire; the lions of French reggae, Dub Inc; Californians Vintage Trouble, a quartet led by charismatic singer Ty Taylor and his primitive soul with a hint of vinyl and jukebox; or afro funk in its purest form from Osibisa. In terms of local groups, stand-out acts include the exquisite pop with a folk twist by Ferran Palau (Anímic), who performs from 'Santa ferida' (2015); instrumental rock from Madrid band, who will make the Fòrum explode with their fourth album, 'IV' (2015); Barcelona band Mi Capitán featuring members of Standstill and Love of Lesbian, which has been one of this year's pop-rock revelations; and the unclassifiable Barcelona line-up Seward.