Much of the typical Sagittarian traits apply to me: Interested in philosophy and religion, impulsive and independent, procrastinate, natural comedians (sometimes exaggerating their adventures to entertain people), but sometimes offend by speaking without thinking, and can be argumentative or blunt. Sagittarians are susceptible to hip troubles and leg pain. Okay so far, but also, Sagittarians are great athletes, big-game hunters and fishermen. HA! All these traits ought to be worked into the song, unless they don’t rhyme. But like I said, I’m having trouble; in fact I pretty much just have words that rhyme but have nothing to do with the zodiac or my real friends. Here’s what I have so far:

All my friends are Sagittarians
We have affinity for philosophy,
Sometimes we act like horse rear ends
Comedians, contrarians, some quinquagenarians
All my friends are Sagittarians
I know some Rastafarians
Braided, bearded, hairy men
Need ganja? They are carryin’
They grow it: they’re agrarian
This woman’s name is Marian,
She is a librarian
‘Til her body turns to carrion
She’ll be Sagittarian
CHORUS

She also is a lesbian
She won’t eat meat or marry men
She’s a vagitarian
So, not all my friends are men
Some are more ovarian
And even imaginary friends
Of mine are Sagittarians
CHORUS
We’re characterized as mutable,
Think everything’s disputable
We’re blunt, unlike our arrow,
Don’t follow the straight and narrow
We’re impulsive but procrastinate
We’re honest but exaggerate
Legs hurt from the brains we’re carryin’
We are proud Sagittarians
CHORUS
See, it’s pretty lame. I invite you to make a much better song, produce it and upload to YouTube and link to it in the comments. When some record label or artist buys it, we’ll split the profits. Or just write some lyrics in the comments. Here’s some leftover words you might use:
Bavarian, Aryan, clarion, barbarian, Bulgarian, Hungarian, non-sectarian, sectarian, Wagnerian, centenarian, grammarian, libertarian, vegetarian, proletarian, seminarian, Unitarian, veterinarian, authoritarian, disciplinarian, egalitarian, humanitarian, octogenarian, parliamentarian, totalitarian, utilitarian, septuagenarian, begins and ends, portends.
(I was going to use the Sagittarius image from this site, because it's pretty right on, but I couldn't get past the misuse of "your" instead of "you're".)