Rosh Hashanah 35 - Who has to pray?
The prayer is said by everyone silently, and then it is repeated by the prayer leader. However, Rabban Gamliel states that the prayer leader's words count as the prayer for everyone, so that everyone else does not have to pray. This is true throughout the year, and even more so on Rosh Hashanah, when the prayer is long and was unfamiliar to many, especially in the times when there were no printed prayer books.
The Sages asked Rabban Gamliel, "According to your opinion that the prayer leader fulfills everyone's obligation, why do people first pray silently at all?" He answers, "To give them something to do while the prayer leader reviews what he is going to say." He then asked in return, "And according to you, why does the prayer leader go down next to the ark and repeat the prayer?" The Sages told him, "For the benefit of the unlearned." He concluded, "Just as the prayer leader's prayer works for the unlearned, so it works for everyone else!"
Some say that Rabban Gamliel exempted even those who are far away in the fields and cannot attend the services. Others say that, just the opposite, he exempted only them, because the circumstances beyond their control stopped them from praying, but those who are in the city and attend services should say the prayers. Today, of course, there are printed prayer books, and everyone is obligated to pray using these.
Art: The Daily Prayers by Leopold Pilichowski