Although Girolamo Frescobaldi's organ works draw on the polyphonic tradition of the Renaissance, few virtuosos of the early 17th century tackled with as much originality the expressive movement that opened the way for what we consider 'Baroque music'. He transposed for the keyboard this sense of the affect and virtuosity that, in the sphere of opera, overturned all the conventions of vocal music. He recommended flexible playing, freed of any overly strict constraints, insisting on the fact that the musician must play 'con affetti cantabili' (with the affects of singing).