Emerson, Lake & Palmer were progressive rock's first supergroup. Greeted by the rock press and the public as something akin to conquering heroes, they succeeded in broadening the audience for progressive rock from hundreds of thousands to tens of millions of listeners. They created a major radio phenomenon as well, penning classic rock radio staples like "Lucky Man," Still…You Turn Me On," and "Karn Evil 9 1st Impression, Pt. 2," and issuing hugely influential albums like Tarkus and Brain Salad Surgery. Their flamboyance on record and in the studio echoed the best work of the heavy metal bands of the era, proving that classical rockers could compete for that arena-scale audience.