With their unique brand of progressive rock, Focus manifested themselves at the start of the '70s as the most successful and appreciated of all the Dutch pop-rock exports. A former Amsterdam Conservatory student, Thijs van Leer (keyboards/flute/vocals) with Martin Dresden (bass) and Hans Cleuver (drums) formed a trio in 1969, they backed several Dutch singers in the late 1960's. At one of their rehearsals Brainbox guitar virtuoso Jan Akkerman stepped in and jammed along with them. The manager of Brainbox, John van Setten found out and kicked him out of the band. This led to Akkerman joining Focus. In 1970 they backed the Dutch version of Hair, they can also be heard on the Dutch Hair album. After their work for the musical they named their band Focus. A few months later Focus recorded their debut album, In And Out Of Focus, released in 1970. After a few months Akkerman wanted to rejoin with his Brainbox mate Pierre van der Linden to form a new band. Van Leer was asked to join them, or to stay with his own trio. He decided to join them. They also asked Cyril Havermans to play bass and do the vocals. This left Dresden and Cleuver aside. With this new line up they worked on their second album. It was produced by Mike Vernon, who would remain their producer throughout their whole career. This was Focus II, or Moving Waves (the name of the album outside the Netherlands). The single Hocus Pocus, with some frantic yodeling and brilliant guitar work, became an enormous hit just as the album did. Focus toured the Netherlands and England and gained a lot of popularity. As another single Sylvia was released and became a hit also. They successfully fuse inspired jazz, rock, and blues improvisation, classical musical structures, and accessible pop melodies into a powerful and instantly recognizable sound.

In 1972 the English magazine Melody Maker voted Focus as "Brightest hope for the year" and "Best foreign group". Furthermore Jan Akkerman was described as the "Best guitarist in the world" and Van der Linden as the "Greatest drummer in Europe". They are one of the most well-known and influential rock bands from the Netherlands.