Pope Francis created 21 new cardinals at a ritual-filled ceremony on Saturday, including key figures at the Vatican and in the field who will help enact his reforms and cement his legacy as he enters a crucial new phase in running the Catholic Church.

On a crisp sunny day filled with cheers from St. Peter’s Square, Francis further expanded his influence on the College of Cardinals who will one day elect his successor: With Saturday’s additions, nearly three-quarters of the voting-age “princes of the church” owe their red hats to the Argentine Jesuit.

In his instructions to the new cardinals at the start of the service, Francis said their variety and geographic diversity would serve the church like musicians in an orchestra, where sometimes they play solos, sometimes as an ensemble.

“Diversity is necessary; it is indispensable. However, each sound must contribute to the common design,” Francis told them.

“This is why mutual listening is essential: each musician must listen to the others.”