Judaism being the oldest and the origin of the Abrahamic religions, it is easy to see how the others adopted certain elements of worship from Judaism, such as chanting and reciting prayers in a musical way. The term a cappella was developed in Italy to refer to chapel music, and then much later evolved into the meaning “without accompaniment”. This being said, the actual practice of a cappella is much older than its name. Judaism and Christianity simply developed this practice into an art form, creating a way to transcribe vocal cues and organize groups of voices.
Torah recitation, I think, is at the heart of Judaism’s use of unaccompanied music. Though it is a more basic form of a cappella in relation to Piyyut and Jewish spirituals, the use of patterns of speech and the addition of melody to verse could be responsible for why the method of recitation of the Quran is so important in Islam. It could also be a device for memorization, in order to pass stories down from generations. I can imagine it must have helped my friends when they were getting bat mitzvahed.
Piyyut is a term referring to a type of Jewish liturgical prayer which is sung / chanted during a service. The prayers are separate from the torah, but incorporated into most services. The tradition of writing these prayers to be sung started around the time Temples started to be built and Jewish communities developed. Most are written in Hebrew, but some were written in Aramaic as well.
Additionally, Piyyuts do not have a melody that is set in stone. Jewish Temples will typically have their own way of singing the song which then becomes a traditional way to sing it within the community. Since it is a form of song that is most often performed unaccompanied, musical accompaniment requires some imagination.
Here is an example of a very well known and loved Piyyut, entitled “Adon Olam”, which is sung joyously, but not always with quite the same melody. This isn’t exactly the best video, but it helps you sort of get a feel for the type of occasion this piece would be performed for, and how well known and inspiring it is to people.
Adon Olam – “Master of the universe”
Adon olam, asher malach,
b'terem kol y'tzir nivra.
L'et na'asah v'cheftzo kol,
azai melech sh'mo nikra.
V'acharey kichlot hakol, l'vado yimloch nora.
V'hu haya, v'hu hoveh, v'hu yih'yeh b'tifara.
V'hu echad, v'eyn sheni l'hamshil lo, l'hachbira.
B'li reishit, b'li tachlit, v'lo ha'oz v'hamisrah.
V'hu Eli, v'chai go'ali, v'tzur chevli b'et tzarah.
V'hu nisi umanos li, m'nat kosi b'yom ekra.
B'yado afkid ruchi b'et ishan v'a'irah.
V'im ruchi g'viyati, Adonai li v'lo ira.
The Lord of the Universe who reigned
before anything was created.
When all was made by his will
He was acknowledged as King.
And when all shall end
He still all alone shall reign.
He was, He is,
and He shall be in glory.
And He is one, and there's no other,
to compare or join Him.
Without beginning, without end
and to Him belongs diminion and power.
And He is my God, my living God.
to Him I flee in time of grief,
and He is my miracle and my refuge,
who answers the day I shall call.
To Him I commit my spirit,
in the time of sleep and awakening,
even if my spirit leaves,
God is with me, I shall not fear.