Many of the pieces were very loud in relation to the amount of instruments involved.  The way the music echoed within the performance hall.  Most pieces had certain bursts of loudness, specifically when they would all chime in together.   The violin would be the loudest of the instruments, mostly because of their pitch and also the abundance of the instrument.  There were many call and responses between the instruments, and when parts of the call and response would repeated, the volume increased.  Also, in order to vary the volume, they also used different strumming or bowing patterns in order to increase sound, for example, they would pluck or play their bow very high on their instruments.