The singers are accompanied by an instrumental group consisting of oboe, bassoon, violin, two violas and basso continuo. As in the case of the singers, the question arises as to whether Bach used one or more players per part. The oboe and the violin are given some important solos, suggesting that there may well have been only one of each. Ton Koopman, for example, uses one oboist and one violinist in his recording. The role of the violas is more to provide accompaniment, filling in harmonies and sometimes doubling vocal lines. The bassoon sometimes supports the continuo section, doubling its bass line, and sometimes plays an independent line.
