The Sao were an African civilization that flourished from ca. the sixth century BCE to as late as the sixteenth century CE. The Sao lived by the Chari River south of Lake Chad in territory that later became part of Cameroon and Chad. They are the earliest people to have left clear traces of their presence in the territory of modern Cameroon. They may have originated in the ancient Near East, in the Nile valley, or near Lake Chad. Sometime around the 16th century, conversion to Islam changed the cultural identity of the former Sao. Today, several ethnic groups of northern Cameroon and southern Chad but particularly the Kotoko claim descent from the civilization of the Sao.

There are several theories concerning the origin of the Sao. Archaeologists J.-P. Lebeuf and A. Masson-Détourbet suggest that the civilisation characterized by city-states may have been influenced by the advanced Nubian civilization of the Nile. According to the historian Dierk Lange, the Sao were immigrants from the ancient Near East in consequence of the fall of the Assyrian Empire at the end of the seventh century BC. Victor Fanso believes that the Sao were the descendants of the Hyksos who conquered Ancient Egypt in the sixteenth century BCE who may have moved southwest from the Nile valley into middle Africa in several waves under pressure from Arab invaders. A more widely accepted theory is that the Sao were simply the indigenous inhabitants of the Lake Chad basin and that their ultimate origins lie south of the lake.

Geoffrey Arnold "Jeff" Beck (born 24 June 1944) is an English rock guitarist. He is one of three noted guitarists to have played with The Yardbirds (Eric Clapton and Jimmy Page are the other two). Beck also formed The Jeff Beck Group and Beck, Bogert & Appice.

Much of Beck's recorded output has been instrumental, with a focus on innovative sound and his releases have spanned genres ranging from blues-rock, heavy metal, jazz fusion and an additional blend of guitar-rock and electronica. Although he recorded two hit albums (in 1975 and 1976) as a solo act, Beck has not established or maintained the sustained commercial success of many of his contemporaries and bandmates. Beck appears on albums by Mick Jagger, Kate Bush, Roger Waters, Donovan, Stevie Wonder, Les Paul, Zucchero, Cyndi Lauper, Brian May and ZZ Top. In 1988, he made a cameo appearance in the movie Twins.

He was ranked 5th in Rolling Stone's list of the "100 Greatest Guitarists of All Time" and the magazine has described him as "one of the most influential lead guitarists in rock".MSNBC has called him a "guitarist's guitarist". Beck has earned wide critical praise and received the Grammy Award for Best Rock Instrumental Performance six times and Grammy Award for Best Pop Instrumental Performance once. He has been inducted into the Rock and Roll Hall of Fame twice: as a member of The Yardbirds (1992) and as a solo artist (2009).