Jonathan Chai (born July 13, 2002) , professionally known by his stage name Mad Tsai, is a Taiwanese and Peruvian singer-songwriter who gained popularity on the app TikTok under the username, "madsteaparty". He gained even more fame when he came out to his mother with his viral song “boy bi”, uploading her reaction to TikTok.

Mad is originally from Huntington Beach, California, and at age 13, began writing music and performing at local shows to help talk about experiences navigating mental health, bullying, self-love, and identity. He was involved in marching band and choir as a teen and picked up the ukulele in high school.

Currently, Mad is based in Los Angeles and occupies the majority of his time as a student at UCLA. He is involved in the university’s acapella group Resonance and is pursuing two majors, music industry/history and English. Mad currently creates music and content whenever he can find the time for it. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.