It is an addictive up-tempo pop dance song called "Peekaboo," which means signature flapping sounds, groovy rhythms and peekaboo, and draws attention by comparing the current generation's lifestyle with cool ways of love to playing in playgrounds and expressing the thrilling feelings felt by new love in lyrics.

It is an R&B pop dance song featuring a melodious bras sauce, and its addictive melody blends well with Red Velvet's cool high notes and colorful ad-libs, adding to the fun of listening to the lyrics boldly expressing interesting feelings toward the strongly attracted "Bad Guy."

The title track "Psycho" is an up-tempo urban pop song that combines Red Velvet's deft yet humorous vocals.

The catchy hook over the ever-changing melody stands out, and the lyrics contain a cool message from a lover who admits that they are the only ones in the end, even though they look like "Psycho."