Koes Plus is an Indonesian music group formed as a continuation of the Koes Brothers group. This band, whose popularity peaked in the 1970s, is considered one of the pioneers of pop and rock and roll music in Indonesia. Although in the course of its history there have been personal changes of members, the most durable and well-known formations are Tonny Koeswoyo (keyboards, melodic guitar), Yon Koeswoyo (rhythmic guitar), Yok Koeswoyo (bass guitar), and Murry (drums and other percussion). All members provide vocals and compose songs.The establishment of Koes Plus was a consequence of the departure of Nomo Koeswoyo from Koes Bersaudara because he chose to pursue a career outside of music. Tonny Koeswoyo, as the most senior member, then recruited Murry and Totok A.R., who were not members of the Koeswoyo family, as replacements for Nomo Koeswoyo and Yok Koeswoyo to play drums and bass guitar. Because then Yok joined, Totok A.R. decided to leave. After Tonnys death in 1987, the lineup for each album or show changed, but with Yon Koeswoyo, he remained in it. The group has been inactive since Yons death in 2018.The color of Koes Plus music is influenced by western music groups that were popular in the 1960s and 1970s, but the originality of his work is still visible. Koes Plus dares to experiment with a wide range of music genres, which can be seen in the various albums it releases. This reflects the competition between various genres of Indonesian music in the 1970s. In addition to playing on the pop genre (with a touch of rock and roll) as the main expression, they also released albums with the genres of dangdut/Malay, pop keroncong, pop in Javanese (with a touch of Javanese and Malay music) and foreign (English and French), and also pop.