Bach's time in Weimar was the start of a sustained period of composing keyboard and orchestral works. He attained the proficiency and confidence to extend the prevailing structures and include influences from abroad. He learned to write dramatic openings and employ the dynamic rhythms and harmonic schemes found in the music of Italians such as Vivaldi, Corelli, and Torelli. Bach absorbed these stylistic aspects in part by transcribing Vivaldi's string and wind concertos for harpsichord and organ; many of these transcribed works are still regularly performed. Bach was particularly attracted to the Italian style, in which one or more solo instruments alternate section-by-section with the full orchestra throughout a movement.[36]