— The Independent (@Independent) June 4, 2017
The concert will be simultaneously broadcast across BBC One, BBC Radio 1, BBC Radio 2, BBC Radio 5 Live and BBC Radio Manchester. It will also be streamed live on BBC iPlayer, MTV, Twitter, Apple Music, Viacom, iHeart Media, ANC, TMC France, and via Ariana's Facebook/Youtube pages.
The website featured in Ariana's tweet: onelovemanchester features links to official online streams, as well as donation and merchandise links.
— Ariana Grande Today (@ArianaTodayNet) June 4, 2017
Ariana will be accompanied for a performance of "My Everything" by the Parrs Wood High School Choir, who performed a rendition of the song after the attack.
Source: 1, 2, 3, 4, 5