Gregorian Chant

A Gregorian Chant is a special type of music heard in the beginning of the original Halo theme, and can be heard at the title screen of Halo: Combat Evolved.

It is just like any other chant, except that vocals are used without lyrics. It is similar to a moan, except that there is a melody that rises and falls.

It is commonly heard in churches, and thus refer to religiousness. It may be put in the Halo theme due to the fact that Halo is a very important artifact to the Covenant's religion.