"That'll Be the Day" is a song written and performed by Buddy Holly and the Crickets. It was released in 1957 and became a huge hit, reaching number three on the Billboard pop singles chart. The song reflects the theme of uncertainty and doubt in a relationship. The lyrics depict a situation where the protagonist's partner threatens to leave, but the protagonist believes it to be a lie. They express their confidence that their partner won't actually leave, stating, "You say you gonna leave, you know it's a lie, 'Cause that'll be the day when I die." The lyrics also highlight the contradictory actions of the partner. They shower the protagonist with affection, love, and material things, but still give hints at the possibility of leaving. Despite this, the protagonist remains hopeful and refuses to believe that their partner will truly go away. The song also mentions Cupid shooting his dart at the partner's heart, suggesting that love has brought them together and that their bond will be difficult to break. However, the protagonist acknowledges that if they ever do part ways, they will eventually feel the sadness and heartbreak themselves. Overall, the song explores the uncertainty and emotional rollercoaster that can come with relationships. It suggests that love, despite its challenges, can be strong enough to alleviate doubts and keep the couple together. Buddy Holly's lively and catchy rock and roll style made the song an enduring classic in the history of popular music.