Long John Baldry formally came out in 1978, an event that was prompted by the release of his album titled "Baldry's Out." This album served as a public announcement of his sexuality and was a significant moment in his career. The album included a song called "A Thrill's A Thrill," which addressed sexuality issues and was indicative of his openness about his identity. Baldry was known for his support of other artists, including Elton John, in their struggles with their own sexuality. His coming out was a pioneering act in the music industry and contributed to the visibility and acceptance of LGBTQ+ artists. For more detailed information, you can refer to sources like Wikipedia and Xtra Magazine.