 Until the late 16th century introduction of the contratenor singers, the tenor was usually the highest voice, assuming the role of providing a foundation.It was also in the 18th century that "tenor" came to signify the male voice that sang such parts.Thus, for earlier repertoire, a line marked 'tenor' indicated the part's role, and not the required voice type; indeed, even as late as the eighteenth century, partbooks labelled 'tenor' might contain parts for a range of voice types.