When I was in hospital a few years ago after having a heart attack, a kindly physiotherapist came to assess how fit I was for further treatment. She wanted to see whether I could walk along the corridor and up a couple of steps without gasping for breath or having palpitations. She rightly erred on the side of caution; once content that I would not react in such an extreme way, she gave me a little bottle of liquid with instructions to spray it under my tongue in the event that I were to have sudden severe chest pains.
You need to have one of these on hand to give to a modern type of liturgist if you ask him whether it is all right to say the Rosary during Mass. Perish the thought! You should be answering the responses, singing the hymns, reading the readings and anything else that is nowadays considered to be the only possible way for you to do that most essential thing of participating. You might find a more discerning liturgist, perhaps a knowledgeable Benedictine, who will tell you that you shouldn’t really read along with the reader, you should be listening to the words as they are proclaimed. Nevertheless, it is more than likely that you will be handed a copy of the text as you enter the Church, with the implied suggestion that you should find the page and follow on.
What do the Popes say?If you want to dig deeper and take a positivistic papal position, you could cite Pope Leo XIII who, in Supremi Apostolatus (1883) n.8 encouraged the celebration of the Mass while people were saying the Rosary, Pope Pius XII who allowed (Mediator Dei (1947) n.108) that the people might lovingly meditate on the mysteries. On the other hand, there is Pope Paul VI who took a different view 24 years later, saying that it was a mistake to recite the Rosary during Mass. (Marialis Cultus (1974) n.48)