Complex sentence: Soon, Granville had a full orchestra at his disposal, so he convinced the management committee to allow him to give classical concerts on Fridays and Sundays, and embarked on advanced concerts of the new composers, as well as his own works.
Split into simpler sentences: Soon, Granville had a full orchestra at his disposal, so he convinced the management committee to allow him to give classical concerts on Fridays and Sundays. He then embarked on advanced concerts of new composers, as well as his own works.