The angels of God have different ranks.

Some are ordinary angels, spoken of as
"sons of God" appear before the Lord only
at appointed times.

Some angels "always behold the face of the
heavenly Father". Gabriel the archangel
is one. When he spoke to Zacharias, he
said, "I am Gabriel that stand in the
presence of God."

In heaven, everyone has their appointed
positions. Because of the importance of
the Trumpet Judgments of the Day of the
Lord, the Seven Angels which stand in the
presence of the God, sound the trumpets.