The first period of Vatican II (1962) was its most crucial; by freeing the Council from the narrow channels of the official drafts, it permitted it to expand its vision and eventually to produce texts that represented and encouraged the three goals Pope John set out for the Council: spiritual renewal, pastoral updating (aggiornamento), and the pursuit of Christian unity.
Four major scenes defined the first act of the conciliar drama; for them I have supplied some useful material:
2) the election of members for conciliar commissions
3) the debate and vote on the liturgy
4) the debate and vote on the draft on the sources of revelation.