The shofar is a ram's horn which is blown somewhat like a trumpet, and 100 notes are blown each day, provided the holiday does not fall on Shabbat. Hearing the shofar is considered one of the most important observances of this holiday, and it is suggested that this sound is a "wake up call" for us to consider our actions and repent. There are four types of shofar notes: tekiah, a 3 second sustained note; shevarim, three 1-second notes rising in tone, teruah, a series of short, staccato notes extending over a period of about 3 seconds; and tekiah gedolah (literally, "great tekiah"), the final blast in a set, which lasts longer than the others.
Religious services for the holiday focus on the concept of God's sovereignty. A special prayer book is used for the High Holy Days, called a Machzor. The melodies of familiar prayers are also different on the High Holy Days. A noted prayer is U'netaneh Tohkef, (let us proclaim the power of God) which conveys how we are judged as we pass before God: "Who shall live and who shall die, who shall see ripe age and who shall not …" This prayer impresses upon us that we are accountable for our actions of the previous year. Another famous prayer of the day is Avinu Malkenu, (Our Parent, Our Ruler,) where we plead, "Deal with us with love and kindness, and help us."
A popular custom during Rosh Hashanah is to eat apples dipped in honey, a symbol of our wish for a sweet new year. We also eat round challah, to symbolize a well rounded, good new year, and also dip the challah in honey. Other popular foods are fish, symbolizing fertility, and many people eat a new fruit of the season, saying the shehekheyanu, a blessing of gratitude and renewal, to acknowledge the new year.
Another popular practice of the holiday is Tashlich ("casting off"). After the Musaf service, we go to a body of flowing water with bread crumbs, which symbolize the sins of the previous year. The act of Tashlich is casting the crumbs, our symbolic sins, into the water, while reciting Pslams of repentance. This practice was developed in the thirteenth century and has grown over the years as it provides time for quiet reflection within nature's beauty.