London’s back on the music map and to pay tribute. Vogue meets the homegrown talents taking grime, R&B and afrobeat worldwide: Yare, Abra Cadabra, Section Boyz, Loyle Carner, Lady Leshurr, Nadia Rose, J Hus, Flohio, Jorja Smith, Stefflon Don and A J Tracey talk style and sound.