How Long

"How Long" is a song recorded and produced by American singer Charlie Puth. He also co-wrote the track with Jacob Kasher and DJ Frank E. The song was released on October 5, 2017, by Atlantic Records as the second single from Puth's upcoming second studio album, Voicenotes (2018). Commercially, it has reached the top 10 in Israel, Malaysia, the Philippines, Scotland, and the United Kingdom as well as the top twenty in Australia, Belgium, Denmark, Ireland, the Netherlands, New Zealand, Slovakia, Spain, and Switzerland.

Background
Charlie teased the song in September 2017 on social media. He tweeted two photos in a row, which were captioned "how" and "long" respectively. In October 2017, he posted photos and video clips of him in the studio with the captions, "has", "this", "been" and "going". On October 4, 2017, he posted a video of the voice note recording behind the song with the caption "on", eventually spelling out "how long has this been going on" altogether, stating the song's hook.