The Piyyut 'Anim Zemirot,' also known as 'Shir HaKavod' (Song of Glory), appears in the Ashkenazi Siddur at the end of the morning prayers, after the Mussaf service. In some Israeli synagogues the prayer was moved to an earlier part of the service, the end of the Shaharit service before the Torah portion. One reason was to assure that the prayer is chanted with intent and by most of the congregation, rather than at the end when the congregants are in a hurry to get home to the late morning Sabbath meal. Some communities only say the prayer on Yom Kippur eve after the Shir Yehud..
One ancient manuscript claims that 'the song was created by our rabbi Yehuda HeHasid of Regensburg,' therefore the Piyyut is attributed to Judah ben Samuel HeHasid, who lived in the 13th century and wrote the Sefer Hasidim. However, in HeHasid's writings it appears that he was familiar with the Piyyut. It is therefore possible that it was written a century or two before him. In Rabbi Jacob Emden's (also know as Ya'avetz) Beit Ya'akov Sidur, an interpretation to one of the last lines of the Piyyut is offered. There the word Rash in the line 'Tikar shirat rash be'eynekha keshir yushar 'al korbonekha,' is interpreted as an allusion to Rabbi Shmuel HeHasid, Yehuda HeHasid's father.
The Piyyut is known as Shir HaKavod (Song of Glory) because it used to be proceeded by the chanting of the verse 'Lift up your heads, O you gates! Lift up, you everlasting doors! And the King of glory shall come in,' (Psalm 24, 9), and possibly because the Piyyut deals with the glory of God.
There are two conventions to chanting the Piyyut. The first is responsorial singing: The Hazzan reads a line and the congregation reads the Piyyut's next line and so forth. In the second convention, the congregation reads the entire text together. In the synagogues where the Piyyut is sung in a responsorial manner, it is customary to let a child who has not yet had his Bar Mitzvah chant the prayer. Some claim that the reason for this custom is because only a young and innocent child can speak to God so directly. It is difficult to decide when this custom began and if it was already practiced in Europe. It can be assumed that Jews of German decent in Israel and other communities that were influenced by them spread this custom.
Lyrically the Piyyut can be split into two parts. In the first part, the Paytan [LEXICON?] asks to describe God, despite the difficulty in doing so because God's greatness cannot be described. The only way to do so is by describing God's actions and deeds on Earth. In the second part, the intimate relationship between God, the Israelites, and Moses is described and there is a request that the Piyyut will please and be accepted by God.
The Piyyut is assembled from lines without verses or a refrain. In every line there is an internal rhyme and there are no rhymes between the different lines. From the fifth line and onwards the first letter of each line forms an acrostic that spells out the Hebrew alphabet.
It is customary to recite the Piyyut when the ark is opened. In his book Shnei Luchos ha-Bris (also known by its abbreviation Shelah) Rabbi Isaiah Horovitz writes that this Piyyut is to be recited at ease. Therefore, some chant it after the Kiddush, while having a snack in the synagogue.
Melodies
This Piyyut has a few melodies associated with it and three in particular that are well-known.
The melody's source is unknown.
This melody is in the minor mode and it most likely originated in the Jewish communities of Germany where it is known with some minor changes: 'Hadar VeHod' during the Mussaf of Rosh HaShanna
This melody is sung in the Ahava Raba mode , and has a faster temperament than the previous two
http://www.piyut.org.il/tradition/3084.html?currPerformance=4048
Chabad Nusah http://www.youtube.com/watch?v=zFLMVDYDaac
This melody was composed by rebbe Shneur Zalman of Liady also known as the Old or Alter Rebbe who was the founder of the Hassidic movement of Habbad. Rabbi Menachem Mendel Schneerson (the Lubavitcher rebbe) who was the seventh Admor of Habad taught this melody to his followers.
In Habbad's songbook Sefer HaNiggunim a story is told about how the melody was passed down. It was after Yom Kippur in a small town, some of the townsfolk went to the synagogue in order to pray and found one of the Polish Hassids dancing by a beam to the melody of Shir HaKavod. The Hassid was so caught up in his dancing that it lasted all night and he forgot to break his fast.
In the Habbad folklore it is believed that the dancing Hassid was the Lubavitch Rebbe.
Additional Melodies
Additional melodies to Shir HaKavod were found that were composed specifically for The High-Holy Days and Simhat Torah.
Furthermore there are modern melodies and adaptations to existing melodies that are sung at festivals and other events and are not sung at synagogues.