[1] The central character in the changing roster, and the only band member present on every album, was conservatory-trained trumpeter Rein van den Broek (10 September 1945 - 11 May 2015).

The band saw some commercial success in the 1970s, having Dutch top ten hit singles with their adaptations of Beethoven's "Fifth" and Bach's "Air".

The group played jazz, pop and R&B covers, but in 1969, shortly after keyboardist Rick van der Linden joined, they were impressed by a gig of The Nice, and van der Linden decided to concentrate on producing classical rock, modern re-interpretations of classical works for rock band.

It quickly became evident that van der Linden had assumed leadership of the group, and in a 1972 press release interview accompanying advance copies of the album Ekseption 5 he openly said so.

Jansen took Ekseption in a jazzier direction, with two LPs of original compositions, but lackluster sales caused the band to break up in 1976.