I’m not sure of the official timeline, but it felt to me that Heardle was a spin off / inspired by Wordle, the game where you have a small amount of guesses to nail a daily word. Heardle was a music version, which was free to play and also insanely popular.
Now, just as Worlde was bought out, so have Heardle: and Spotify are the buyers. They’ve vowed to keep it free, keep the format, but add the ability to listen to the full song at the end. However, users are reporting faults, histories being erased, and general doubts.
Spotify’s Head of Music (Jeremy Erlich) said “Heardle has proven to be a really fun way to connect millions of fans with songs they know and love and with new songs… and a way to compete with their friends as to who has the best musical knowledge… Since its debut, the game has quickly built a loyal following, and it aligns with our plans to deepen interactivity across the Spotify ecosystem…”