Answer by taking a quote from the following article:

Sun Ra (born Herman Poole Blount, legal name Le Sony'r Ra; May 22, 1914 - May 30, 1993) was an American jazz composer, bandleader, piano and synthesizer player, and poet known for his experimental music, "cosmic" philosophy, prolific output, and theatrical performances. For much of his career, Ra led "The Arkestra", an ensemble with an ever-changing name and flexible line-up. Born and raised in Alabama, Blount eventually became involved in the Chicago jazz scene during the 1940s. He soon abandoned his birth name, taking the name Sun Ra (after Ra, the Egyptian God of the Sun) and developing a complex persona and mythology that would make him a pioneer of Afrofuturism: he claimed he was an alien from Saturn on a mission to preach peace, and throughout his life he consistently denied any ties to his prior identity.

According to Szwed, Sun Ra's view of his relationship to black people and black cultures "changed drastically" over time. Initially, Sun Ra identified closely with broader struggles for black power, black political influence, and black identity, and saw his own music as a key element in educating and liberating blacks. But by the heyday of Black Power radicalism in the 1960s, Sun Ra was expressing disillusionment with these aims. He denied feeling closely connected to any race. In 1970 he said:  I couldn't approach black people with the truth because they like lies. They live lies... At one time I felt that white people were to blame for everything, but then I found out that they were just puppets and pawns of some greater force, which has been using them... Some force is having a good time [manipulating black and white people] and looking, enjoying itself up in a reserved seat, wondering, "I wonder when they're going to wake up."  Sun Ra is considered to be an early pioneer of the Afrofuturist movement due to his music, writings and other works.  The influence of Sun Ra can be seen throughout many aspects of black music. He grounded his practice of Afrofuturism in a musical tradition of performing blackness that remains relevant today. Sun Ra lived out his beliefs of Afrofuturism in his daily life by embodying the movement not only in his music, but also in his clothes and actions. This embodiment of the narrative allowed him to demonstrate black nationalism as a counternarrative to the present culture. It was in Chicago, as well, in the mid-fifties, that Ra began experimenting with extraterrestriality in his stage show, sometimes playing regular cocktail lounges dressed in space suits and ancient Egyptian regalia. By placing his band and performances in space and extraterrestrial environments Sun Ra built a world that was his own view of how the African diaspora connected.

What did Ra say the blacks should do?
This embodiment of the narrative allowed him to demonstrate black nationalism as a counternarrative to the present culture.