911 / Mr. Lonely

Following a week of teasing, Tyler, the Creator released a music video for a track titled "Who Dat Boy" on June 30, 2017. At the end of the video, another track was played, which was "911", the first part of the track.^[2] Following the release of the video, the songs were officially released together on streaming services the same day, as the lead singles from Flower Boy.^[3][4]

"911 / Mr. Lonely" is a two-part track, with the first part, "911", being described as "sunny and joyful" with synths and a bass described by Pitchfork as "soulful" playing, as the first part of the track contains an interpolation of "Outstanding" by the Gap Band. The lyrics of this part of described as a "heartstick Tyler", as he fails to take pleasure in anything without his lover. Steve Lacy and Anna of the North sing the chorus and the bridge, while Frank Ocean's verse has him singing about remembering a lover that would pick him up from the suburbs.

The track's second part, "Mr. Lonely", contrasts from "911", with a "thunderous" drum pattern and stuttering hi-hats, and involves Tyler rapping about his condition; "I say the loudest in the room/Is prolly the loneliest in the room/It's me".^[5]