We sing a song
of seeming silence.
Only one of us
is without voice.
We are conventional.
Not at all rare.
But steadfast?
Encompassing?
That is not our affair.
Courtesy you can have
from two,
Comportment is not
known to the rest of the crew.
Altair Astrology 
Greetings Thomas, 🙂
Thanks for another treat ! Yummy ! 🙂
How about:
Mutable signs (also called common signs or bicorporeal or double-bodied signs)
Gemini, Virgo, Sagittarius, Pisces.
We sing a song (sign=sign)
of seeming silence. (Mutable = Mute able) 😉
Only one of us
is without voice. (Pisces is mute)
We are conventional. (Common)
Not at all rare. (Common)
But steadfast? (not Fixed)
Encompassing? (not Cardinal=4 directions on the compass)
That is not our affair.
Courtesy you can have
from two, (Virgo and Pisces )
Comportment is not
known to the rest of the crew. (Gemini and Sagittarius, them unrestrained twins, often misbehave, shame on them. LOL) 😉
Cheers,
Twiddle
(not a wild twin)
Ah, yes !
Courtesy you can have
from two,
Comportment is not
known to the rest of the crew.
A Fishy Venus and Virgoan Merc are dignified by exaltation.
But when exchanging signs , these 2 planets fall.
Gemini and Sagittarius treat no-one with admiration,
They exalt nobody ! They show no courtesy at all !
Greetings Twiddle! 🙂
And a happy St. Nicholas day!
Excellent answer. Once again you have guessed it right.
In the last clue I was thinking about humane signs and bestial or at least partially so! Though I like both of your interpretations! 😉
Cheers,
Thomas