From groundbreaking albums to boundary-pushing discussions of sexuality, LGBT musicians have played a major role in popular music. In honor of LGBT history month, here’s a list of five musicians that broke ground in both their genre and the progression of sex equality.

David Bowie

After his breakout hit “Space Oddity” in 1969, David Bowie quickly became one of the most innovative artists of both his time and modern music history, experimenting with strange song structures and themes such as spirituality and finding his role in society. Paired with his ever-changing visual album themes, Bowie’s endeavors became known as some of the best art rock had to offer.

Although Bowie came out as gay in 1972, he later stated in 1976 that he was bisexual, and eventually went on to say his declaration of bisexuality was “the biggest mistake [he] ever made” because it forced him to become an image for LGBT rights. His critically acclaimed masterpiece Ziggy Stardust incorporated sexuality as a central theme, expressing Bowie’s feelings as an alienated outsider to the world.

Freddie Mercury

Throughout his career, Queen lead singer Freddie Mercury was constantly churning out some of the greatest cutting-edge pop the world had ever heard. Queen’s list of hits is never ending, and to this day Mercury’s lyrics are played on the radio and sung throughout stadiums across nations. Mercury was a true showman, using his legendary voice to put on some of the most renowned live shows of all time, including Queen’s famous performances at Wembley Stadium in 1986 and their 1985 show for Live Aid.

Known for his flamboyant and bombastic stage presence, Mercury was the complete opposite off-stage. He preferred to keep his private life quiet, and although he wasn’t afraid to express his sexuality, Mercury never allied himself with LGBT causes. Nonetheless, his image stands as one of the most prolific of its kind.

Michael Stipe

Although his band’s name would imply their music is dreamy and sleepy, Michael Stipe and R.E.M were anything but, portraying a vibrant and mysterious image. Their exploration of new sounds with orchestral scores and exotic instrumentation turned them from cult favorites to rock stars, keeping pop hooks at their core and building upon them with ease. As lead singer of the band, Stipe was their unwilling figurehead, finding himself at the forefront of one of the fastest growing bands in the world, and eventually finding his groove writing some of the most poetic lyrics of his time.

During his band’s peak success following their hit albums Out of Time and Automatic for the People, rumors that Stipe had contracted HIV began to circulate, and questions about his sexuality followed. Although the HIV rumors were false, Stipe came out in 1994, not defining himself as gay or bisexual, but as queer, or in his own words, “an equal opportunity lech.”

Melissa Etheridge

Melissa Etheridge might be the perfect musician. She’s a fantastic singer, can write a great hook and expresses heartache and joy through her lyrics, all while carrying the swagger of a rock star. Her self-titled debut kicked off her career, but it wasn’t until 1993’s Yes I Am that her lesbian angst and blues rock riffs hit the mainstream.

Etheridge is a prominent activist for the LGBT community. As one of the first high-profile gay celebrities to have children, Etheridge has helped push boundaries for public acceptance of LGBT families and fostered the relationship between gay and straight Christians.

Frank Ocean

Frank Ocean prefers to keep a low profile with nearly everything, including his sexuality. He didn’t come out until 2012, when he posted a blurb on his Tumblr including, “I don’t know what happens now, and that’s alrite. I don’t have any secrets I need kept anymore … I feel like a free man.” He has since written think pieces for his Tumblr about the upcoming presidential election and the recent shooting at a gay nightclub in Orlando.

From the beginning of his first mixtape, nostalgia, ULTRA., former Odd Future cohort Frank Ocean made it obvious he didn’t support the homophobia of the other artists in the collective. In “We All Try,” Ocean hits the ground running, singing, “I believe that marriage isn’t between a man and woman but between love and love.” Since, he’s written some of the most heart-wrenching love tales of all time, including “Ivy” on his most recent LP, Blonde, which tells the story of Ocean’s first love at the age of 19.