Final answer:
T. Rex, originally known as Tyrannosaurus Rex and formulated by Marc Bolan and Steve Peregrin Took, was a folk duo that evolved into a significant pioneer of Glam Rock.
Step-by-step explanation:
The band that started as a folk duo and were some of the original pioneers of Glam Rock was T. Rex, initially known as Tyrannosaurus Rex. Formed by Marc Bolan and Steve Peregrin Took, T. Rex transitioned from their folky beginnings to become one of the most iconic bands of the Glam Rock movement in the early 1970s. Hits like “Bang a Gong (Get It On)” and “Jeepster” with their distinctive, futuristic sound and Bolan's flamboyant stage presence set the scene for Glam Rock's combination of outrageous fashion, theatrical performances, and innovative music.