During their third period, beginning in the 1970s and onward, Sun Ra and the Arkestra settled down into a relatively conventional sound, often incorporating swing standards, though their records and concerts were still highly eclectic and energetic, and typically included at least one lengthy, semi-improvised percussion jam. Sun Ra was explicitly asserting a continuity with the ignored jazz tradition: “They tried to fool you, now I got to school you, about jazz, all about jazz” he rapped, framing the inclusion of pieces by Fletcher Henderson and Jelly Roll Morton. In the 1970s Sun Ra took a liking to the films of Walt Disney. He incorporated smatterings of Disney musical numbers into many of his performances from then on. In the late 1980s the Arkestra performed a concert at Walt Disney World. The Arkestra’s version of “Pink Elephants on Parade” is available on Stay Awake, a tribute album of Disney tunes played by various artists and produced by Hal Willner. A number of Sun Ra’s 1970s concerts are available on CD, but none have received a wide release in comparison to his earlier music. The album Atlantis can be considered the landmark that led into his 1970s era. In 1978-1980 performances, Sun Ra added a large electronic creation, the Outerspace Visual Communicator, which produced images rather than sounds; this was performed at a keyboard by its inventor, Bill Sebastian. During concerts, the OVC usually was positioned at center stage behind the Arkestra while Sebastian sat on stage with the musicians.