atferrari, You right in so much as a lot of work went into the set-up of the voices , styles and registrations, voices are actual instrument samples usually , many 100 to choose from and combine including choirs and effects. styles are the accompaniment the rhythm also 100's , registrations pull it all together , the lights above the lower manual show the registrations programmed for each bar of music, these can be automatically or manually advanced , so as well as the keyboard keys and music there are a lot of other things to think of ....