Genuinely; with authority; SYN. genuinely.

ETYM Cf. French authenticité.
Quality of that which is authentic; true and legitimate; SYN. genuineness, legitimacy.
In music, a trend initiated in Britain 1970 aiming to reproduce the original conditions of early music performance and instrumentation as a means of rediscovering esthetic terms of reference. It stimulated important practical research in manuscript editing and transcription, instrumentmaking, dance, architectural acoustics, and vocal techniques and encouraged performance of vocal works in the original language.
Notable exponents include conductors Raymond Leppard, Christopher Hogwood, Andrew Parrott, and Roger Norrington, David Munrow (woodwind), Anthony Rooley (lute), Jaap Schröder (violin), Emma Kirkby (soprano), and Frans Brüggen (flute).