Om - The Sound of Music Om or Aum (ॐ or औं) is not pronounced as one sound but four instead, each making up one note in a 4/4 time signature as is used in most music:
1/4 - The first sound is the vowel 'a' (अ).
2/4 - Then it transitions towards the vowel 'u' (उ) in the front of the mouth to create the sound 'au' (औ).
3/4 - Then the consonant 'm' (म) is vocalised, ending the sound.
4/4 - Finally there is a note of silence which follows, similar to a pause in modern sheet music.
It is thus said to be the origin of all music and the source of this standard time signature of music.
It is also considered the origin of all speech as it spans the length of the human vocal range from 'ah' at the start of the Sanskrit alphabet and at the back of the velum/throat through to the front of the mouth with the labial sounds 'u' and 'm' which both require use of the lips.
Thus like the alpha and omega, all possible vowels and consonants lie in between the phonemes of 'a', 'u' and 'm' that constitute the Aum ॐ.
