Shulchan Aruch (619:1) states, "One should not change the custom of his city, not even with the nigunim or the piyutim they say." The Mishnah Berurah explains, מתבלבל זה ידי על כי הקהל דעת, "This confuses the community." Furthermore, the holy sefarim teach that the traditional tunes of Rosh Hashanah and Yom Kippur have the power to remove the harsh judgment. One of the translations of the word זמירות is to prune, the other translation is song. Accordingly (Tehillim 47) לאלקים זמרו means the harsh judgment is pruned away with song.
There was once a king whose young son had gone insane and was sent to a mental asylum. The asylum profited from hosting this royal patient because the king upgraded the services of the asylum so his son would receive the best care.
The prince’s condition improved with time, but the institution’s directors did not tell the king of his progress. They wanted to keep the prince in their facilities as long as possible.
The prince tried to escape and go home, but the doors were always locked. The prince wrote letters to his parents, explaining that he was healed and wanted to go home, but those letters were discarded and never sent.
Once, the king's son scribbled on a page and gave it to one of the directors, asking him to send it to his father. This time, the director was glad to comply and to send the letter because this letter proved that he still needed help. What normal child of his age would send a scribbled paper to his father? The directors didn't realize that the prince concealed a hidden message within the illegible message. Concealed was a plea to his father, the king, to bring him home, because he was better.
When the king received the letter, at first, he was disappointed that his son had fallen to such a state. But then he studied the letter from all angles and picked up on the hidden message. He came to the asylum and brought his son home.
This parable explains why we use the specific tunes and melodies on Rosh Hashanah and Yom Kippur. We say many tefillos to the King, our Father in heaven, but the angels intercept our tefillos and don't let the requests ascend to heaven. Therefore, we sing melodies. The malachim don't understand their importance, so they allow the songs to go up. Concealed within these tunes are our yearnings, repentances, and requests for the upcoming year. Hashem understands the hidden messages and grants us a good year.
