The Amsterdam Baroque Orchestra is not a full-time ensemble, but nevertheless a quite busy group of about 26 or so musicians, many of international renown, who assemble several times yearly to perform a series of concerts devoted mostly to Baroque-era music. The repertory range falls in the period 1600 to 1791 (the year of Mozart's death, not a coincidental cutoff point, according to the group's founder, conductor Ton Koopman). The ABO regularly appears on recordings, its discography actually outpacing its concert work in later years. Perhaps the recording project the ABO is best known for is a cycle of the J.S. Bach cantatas (sacred as well as secular), which by its 2004 completion, ran to well over 20 volumes (67 discs in a 2007 release of the complete set). Of course, this massive undertaking would be impossible without a choir, and the ABO fields its own, with a talented ensemble of mostly Dutch singers that can range from around 15 to over 30 members. The ABO has appeared on more than 50 recordings, mostly for the Challenge Classics and Erato labels. The Amsterdam Baroque Orchestra was founded by Ton Koopman in 1979. Most of the players had already earned international reputations for their work in Baroque repertory. Typically, the ABO would perform in Amsterdam (the Concertgebouw), the Hague, Utrecht, Rotterdam, as well as in other major concert halls throughout Europe and the U.S.: New York's Lincoln Center, London's Barbican Center, Paris' Théâtre des Champs-Elysées, and the Vienna Musikverein are among the many major concert venues in which it has scored critical success. By the 1990s the group was among the most celebrated Baroque ensembles in Europe. In 1992 Koopman founded the Amsterdam Baroque Choir, which debuted at the Holland Festival of Early Music that year with a Biber Requiem and Vespers. In 1994 Koopman and the ABO and Choir launched the massive Bach cantata undertaking for the Erato label. The latter half of the cycle was issued on the Challenge Classics label, however. The ABO and Choir have received numerous awards for their recordings: the first four issues in the Bach project received the 1997 Deutsche Schallplattenpreis Echo Klassik, and other citations included a Gramophone Award, a Diapason d'Or, and two Edison Awards. Among the more important later recordings by the ABO and Choir was a June 2007 Kultur Video DVD of five J.S. Bach religious cantatas.