Theo

Theo (테오), born Choi Tae-yang (최태양) on July 1, 2001, in Daejeon, South Korea, is the oldest member and lead vocalist of P1Harmony under FNC Entertainment. He is also a guitarist and contributing songwriter, threading a quieter creative voice through P1Harmony's conceptually dense releases. Theo trained under FNC before debuting with P1Harmony on October 28, 2020, with the mini album Disharmony: Stand Out. His smooth, warm mid-range tone became one of the group's defining sonic signatures through six mini albums in the Disharmony and Harmony series from 2020 to 2023. Where some K-pop vocalists lean into flash, Theo's style is controlled and measured -- his parts often the melodic anchor in songs that lean heavier on production. In 2025, P1Harmony released DUH! and then EX, their first full English-language EP, reflecting the group's growing international fanbase and a strategic pivot toward global markets. In March 2026, they followed with the mini album Unique. Theo's Spotify presence includes both group output and occasional individual material that showcases the more introspective side of his voice. Fans have long described him as the group's emotional anchor -- steady in performance, understated in public, with a focus that communicates more than his minimal social presence suggests.