Focus is a Dutch progressive rock band, established in Amsterdam in 1969. Led by classically trained organist and flutist Thijs van Leer, the band is known for its unique blend of classical, jazz, and rock music, exemplified by their signature instrumental track "Hocus Pocus". Their innovative use of the yodel and the accordion in rock music, along with the technical proficiency of the band members, notably guitarist Jan Akkerman, has firmly established Focus as a significant figure in the progressive rock genre. Throughout their career, they have influenced numerous musicians and have made a lasting impact on the development of experimental rock.