1970: At the release of their first album In and Out of Focus, Focus comprised keyboardist and flautist Thijs van Leer, guitarist Jan Akkerman, bass guitarist Martin Dresden, and drummer Hans Cleuver. The album was little noticed outside of the Netherlands, where a small but avid fan base developed. Akkerman left the group to form another band with bassist Cyril Havermans and Pierre van der Linden, a drummer he had previously performed with in Johnny and the Cellar Rockers, The Hunters, and Brainbox. When Cleuver and Dresden left Focus shortly after, Van Leer joined Akkerman, Van der Linden, and Havermans as the new lineup of Focus.
1971: The group released Moving Waves, which brought the band international acclaim and a hit on both sides of the Atlantic with the radio edit of the rock rondo Hocus Pocus. This rock classic consists of Akkerman's guitar chord sequence used as a recurring theme, with quirky and energetic interludes that include alto flute riffs, accordion, guitar, and drum solos, whistling, nonsensical vocals, falsetto singing, and yodeling. This album established Thijs van Leer and Akkerman as composers who could appeal to progressive-rock album listeners (a large audience in the early 1970s) and radio single buyers.
Shortly before the band went on tour to support the album, Havermans quit and was replaced by Bert Ruiter. He released a solo album, Cyril, in 1973, on which he was backed by all three of his former bandmates from Focus.
1972: The Focus III double album was released. Van Leer and Akkerman were still producing much of their most seminal work, but critics claimed that the album was not as cohesive as Moving Waves and the material did not support the length of a double album. However, the album contained the Van Leer-penned "Sylvia" which become a major hit in many markets outside the U.S. and was in the charts for several weeks in Great Britain. After two hits in a row, demands to continue producing hit singles began both inside and outside the ranks of the band and its producers.
In late 1973, the Focus "At the Rainbow" album was released, which showcases the energy and virtuosity Focus routinely displayed in their live concerts.
1974: Van der Linden was replaced by ex-Stone the Crows drummer Colin Allen before the Focus recorded the Hamburger Concerto album. It was felt by the producers and some in the group that Allen's more mainstream rock drumming style would make Focus more accessible to a wider audience. An attempt to repeat the chart-topping performance of the "Hocus Pocus" sound in the single Harem Scarem was not successful, and this contributed to the band's declining fortunes at this time. However, Hamburger Concerto is still considered by many to be their masterpiece, despite the New Musical Express review which qualified the hamburger as being "overdone".
1975: The album Mother Focus, featuring new drummer David Kemper, was released to mostly negative reviews. Critics and longtime fans were puzzled by the sudden turn to short pop songs and a light jazz-fusion style in several tracks, while the lack of a potential single soured the music industry's opinion on the band's ability to capture a wider audience. The quality of the compositions were still high, but the career of Focus was hampered by changing tastes in the audience away from the progressive music that was in vogue when the band started and the lack of a clear stylistic direction.
1976: Frustrated with group's lack of direction and the constraints of working with its commercial ambitions, Jan Akkerman left on the eve of a sell-out UK tour. His last minute replacement was Belgian jazz-fusion guitarist Philip Catherine. The group's label Sire Records released Ship of Memories, an album of largely unfinished Focus tracks from the aborted 1973-1974 rehearsal sessions to produce a follow-up album to Focus 3. The liner notes were written by Mike Vernon who was the group's producer at the time, and claim that Akkerman's lack of interest in the project was the reason the sessions fell through. Ship of Memories was released largely due to the effort of Mike Vernon and without the active involvement of the band. The title track is a Van der Linden composition.
1978: American singer P. J. Proby and guitarist Eef Albers joined Philip Catherine and the rest of Focus to record Focus con Proby. The album received dismal reviews and a lack of interest from all but hardcore fans, and after a short tour the band decided to call it a day.
1985: Van Leer and Akkerman reunited for a joint project which resulted in the commercially unsuccessful album "Focus". Even though it is officially not a product of the band Focus, most tracks recall the "lite jazz" sound of the "Mother Focus" album. With tepid marketing support and a short record production run, many of Focus' longtime fans around the world were unaware that the album was released or were unable to find a copy. As a result, sa