The shofar

The shofar is blown on many different occasions: on the Jubilee Year, on Rosh Hashana (New Years), also called Yom Teru'ah (the day of blowing,), in religious rites, or as a call to war. Today the shofar is synonymous with the High Holy Days.

The shofar calls

The Tekiah: the "blast," one long blast with a clear tone.
Tekiah

The Shevarim: a "broken," sighing sound of three short calls.
Shevarim

The Teruah: the "alarm," a rapid series of nine or more very short notes.
Teruah

The Tekiah Gedolah: "the great Tekiah," a single unbroken blast, held as long as possible.
In fact there is no certainty on what a teruah sound really is. It could be a shevarim, a teruah or a combination of both. On Rosh Hashana, several combinations are used to accommodate the various opinions.
Why is the shofar so important to the Jewish people?

The command to blow the shofar is given in the Torah without explanation, but Rabbis have provided many interpretations to the meaning of the Shofar. Maimonides (Jewish philosopher and physician born in Spain in the 12 century) writes:
" Awake, sleepers from your sleep! Arise, slumberers, from your slumber! Scrutinize your deeds and return to repentence and remember your creator! Those forgetters of the truth in the vanities of time and those who stray all their year in vanity and emptiness which can neither help nor save. Look to your souls, better your ways and deeds. Let each one of you abandon your evil way and your thoughtrs which are not good."
Hilkhot Teshuvah, chapter 3

The shofar symbolizes the major theme of the Days of Repentence, during which we commemorate the beginning of the world. We try to make a new start within ourselves, and to return to the beginning of the cycle. The shofar, with its powerful and profound calls, removes the obstacles before us and helps us reach this new start.