Do not have wings. (The first artistic depiction of angels with wings wasn't until the fourth century AD.)
Do not play harps. (Trumpets maybe.)
Do not wear halos.
Are not cherubs. (See below.)
Young angels do not come to earth for an apprenticeship.
Young children who die do not become angels.
Cherubs and Seraphs:
Are not angels.
Do have wings. (Four. Or six. That make a loud noise.)
And four faces.
With many eyes.
Are God's bodyguard.
Are certainly not 'cherubic'.
On a summer's Sunday evening do I dare
To hear Mrs. Adlam's angels in the air
From 'Mrs Adlam's Angels' by Ralph McTell
Full lyrics in 'Time's Poems', p 394
"Sundays as a rule us kids went to Sunday School."
Among the characters Ralph McTell remembers from Sunday School at the Mint Walk Mission in Croydon was "...a lovely old lady organist and shining Christian in the form of Mrs. Lily Adlam." ('Angel Laughter', p. 76; 'As Far As I Can Tell', p. 60.)
That's all Ralph tells us about Mrs Adlam in his autobiography; but a memory of something she said prompted him to write 'Mrs Adlam's Angels':
Mrs. Adlam said
Angels stood round our bed
To keep us safe from dark
The word 'angel' derives from the Latin for 'messenger'. Angels might deliver their message in person, as when Gabriel told Mary she would have a baby (Luke 1: 26 - 33).
Or in a dream, as when Joseph was told to take Mary and Jesus to Egypt to escape Herod (Matthew 2: 13).
Or even in a lions' den, as when an angel came to protect Daniel (Daniel 6: 21 - 22).
It was from stories such as these that the idea of 'guardian angels' arose. Indeed, Jesus himself suggested that children have angels in heaven assigned to their care (Matthew 18: 10).
...though we never saw one anywhere
In the days of the prophet Elisha, Israel and Syria were at war. The Syrians had surrounded the city, and Elisha's servant was frightened. “Don’t worry about it", Elisha told him. "We have them outnumbered". And the servant looked and saw a heavenly army of horsemen on fiery chariots all around them (2 Kings 6: 15 - 17).
Yahweh is often called 'Yahweh of Armies', and Elisha's servant saw the reality of God's spiritual forces.
Just because 'we never saw one' doesn't mean they weren't there.
We heard them softly singing in the air
All together now: 'Hark! The herald angels sing…'
Unfortunately, there is no record in the Bible of angelic singing. That's not to say they don't; it's just that the Bible doesn't say they do. The armies of heaven whom the shepherds saw the night Jesus was born praised God and said, "Glory to God in the highest…" (Luke 2: 13 - 14).
...all our mates were playing
With Mrs. Adlam's angels
The writer to the Hebrews says, "Don’t forget to be hospitable to strangers. Some people have welcomed angels without knowing it." (Hebrews 13: 2).
I wonder if her angels
Have their arms around her curled
Keeping her safe from life
And guarding her from the world
Angels in the Bible:
Small Voice Calling > The Call > Angels
Small Voice Calling