such as mambo, tango, or bossa nova. Chamberlin Rhythmate (1957) In 1957, Harry Chamberlin, an engineer from Iowa, created the Chamberlin Rhythmate, which allowed users to select between 14 tape loops of drum kits and percussion instruments performing various beats. Like the Chamberlin keyboard, the Rhythmate was intended for family singalongs. Around 100 units were sold. First commercial product – Wurlitzer Side Man (1959) In 1959, Wurlitzer released the Side Man, which generates sounds mechanically by a rotating disc, similar to a music box. A slider controls the tempo (between 34 and 150 beats per minute). Sounds can also be triggered individually through buttons on a control panel. The Side Man was a success and drew criticism from the American Federation of Musicians, which ruled in 1961 that its local jurisdictions could not prohibit Side Man use, though it could not be used for dancing. Wurlitzer ceased production of the Sideman in 1969. Raymond Scott (1960–1963) In 1960, Raymond Scott constructed the Rhythm Synthesizer and, in 1963, a drum machine called Bandito the Bongo Artist. Scott's machines were used for recording his album Soothing Sounds for Baby series (1964). First fully transistorized drum machines – Seeburg/Gulbransen (1964) During the 1960s, the implementation of rhythm machines were evolved into fully solid-state (transistorized) from early electro-mechanical with vacuum tubes, and also size was reduced to desktop size from earlier floor type. In the early 1960s, a home organ manufacturer, Gulbransen (later acquired by Fender) cooperated with an automatic musical equipment manufacturer Seeburg Corporation, and released early compact rhythm machines Rhythm Prince (PRP), although, at that time, these sizes were still as large as small guitar amp head, due to the use of bulky electro-mechanical pattern generators. Then in 1964, Seeburg invented a compact electronic rhythm pattern generator using "diode matrix" ( in 1967), and fully transistorized electronic rhythm machine with pre-programmed patterns, Select-A-Rhythm (SAR1), was released. As a result of its robustness and enough compact size, these rhythm machines were gradually installed on the electronic organ as an accompaniment of organists and finally spread widely. Keio-Giken (Korg), Nippon Columbia, and Ace Tone (1963–1967) In the early 1960s, a nightclub owner in Tokyo, Tsutomu Katoh was consulted by a notable accordion player, Tadashi Osanai, about the rhythm machine he used for accompaniment in the club, a Wurlitzer Side Man. Osanai, a graduate of the Department of Mechanical Engineering at the University of Tokyo,