If surviving medieval folk rock bands shifted towards more mainstream progressive rock, progressive rock bands often included early music among their influences. Despite emerging from the British blues boom, the vocal style of Ian Anderson of Jethro Tull was often compared with a medieval troubadour, while the signature sound of his flute, later combined with the keyboard and stringed instrumental skills of the band, lent itself to a medieval element of the music.
Ian Anderson
Jethro Tull