For the most part, Tegan and Sara each sing the songs that they have written. There are a few exceptions where Sara sings a song Tegan has written in live performances, they have been noted accordingly.

Yellow Demo
Here I Am –Tegan
Falling Asleep –Tegan
Hello –Sara
Just Me –Tegan
Star Money –Tegan

Under Feet Like Ours (1999)
Divided –Tegan
Our Trees –Tegan
Come On –Sara
Freedom –Tegan
Proud –Sara
More For Me –Tegan
Hype –Sara
Clever Meals –Tegan
This Is Everything –Tegan
Heavy –Sara
Welcome Home –Tegan
Superstar –Tegan

This Business of Art (2000)
The First –Tegan
Proud –Sara
Frozen –Tegan
Hype –Sara
My Number –Tegan
All You Got –Sara
Freedom –Tegan
Not With You –Sara
More For Me –Tegan
Come On –Sara
Superstar –Tegan

If It Was You (2002)
Time Running –Tegan
You Went Away –Tegan
Monday Monday Monday –Sara
City Girl –Tegan, sometimes sung by Sara in live performances
Not Tonight –Sara
Underwater –Sara
I Hear Noises –Tegan
Living Room –Tegan
Terrible Storm –Sara
And Darling –Tegan
Want to Be Bad –Sara
Don’t Confess –Tegan

So Jealous (2004)
You Wouldn’t Like Me –Tegan
Take Me Anywhere –Tegan
I Bet It Stung –Sara
I Know I Know I Know –Tegan
Where Does The Good Go –Tegan
Downtown –Sara
I Won’t Be Left –Tegan
Walking With A Ghost –Sara
So Jealous –Sara
Speak Slow –Tegan
Wake Up Exhausted –Tegan
We Didn’t Do It –Sara
Fix You Up –Tegan
I Can’t Take It –Sara

The Con (2007)
I Was Married –Sara
Relief Next To Me –Sara
The Con –Tegan
Knife Going In –Sara
Are You Ten Years Ago –Tegan
Back In Your Head –Sara
Hop A Plane –Tegan
Soil, Soil –Tegan
Burn Your Life Down –Sara
Nineteen –Tegan
Floorplan –Sara
Like O, Like H –Sara
Dark Come Soon –Tegan
Call It Off –Tegan

Other Releases (Singles, EPs, etc.)
Come On Kids –Tegan
Empty In Between –Tegan
One Second–Tegan
His Love –Tegan
I Take All The Blame–Sara

Unreleased
Buried Alive –Tegan
Don’t Be Cruel –Tegan
Don’t Go Looking –Tegan
Give Chase –Tegan
Goodbye –Tegan
Infamous –Tegan
I’ve Got You/ When I Get Up –Tegan
Lately –Tegan
Left Me To Wonder –Tegan
Love Type Thing –Sara
Missing You –Tegan
Morning Comes –Tegan
One Month –Tegan
Trouble –Sara
Your Game –Tegan
Your Love –Tegan

Tegan and Sara sometimes talk about the inspirations for and meaning of their songs in interviews and at shows. If there’s a particular song you’re curious about try asking about it on the message board or on the livejournal community.

Against Me! Borne On The FM Waves featuring Tegan Quin
Vivek Shraya Your Name featuring Sara Quin
The Reason We’re So Beyond This featuring Sara Quin
Melissa Ferrick Never Give Up featuring Tegan Quin
Kinnie Star La Le La La featuring Tegan Quin
Rachel Cantu Saturday featuring Tegan Quin
Vivek ShrayaThe Alphabet featuring Tegan Quin
David Usher Hey Kids featuring Tegan Quin

The Rentals Man with Two Brains covered by Sara Quin
The Bangles In Your Room covered by Sara Quin
David Bowie Rebel, Rebel covered by Sara Quin
R.E.M. Sweetness Follows covered by Sara Quin
Bruce Springsteen Dancing in the Dark covered by Sara Quin
Flock of Seagulls I Ran (So Far Away) covered by Sara Quin
Prince When You Were Mine covered by Sara Quin
Rhianna Umbrella covered by Sara Quin

Tegan:
Upper Right Arm –black symbol
Outer Right Forearm –colourful tree
Outer Left Arm near Elbow –black symbol
Inner Left Forearm –colourful tree with heart
Upper Right Bicep –beginning of quote from Bruce Springsteen’s The Human Touch “What you don’t surrender” by Justina Kervel
Upper Left Bicep –continuation of quote from Bruce Springsteen’s The Human Touch “the world just strips away” by Justina Kervel

Sara:
Inner Left Forearm – symbol that looks like a capital E with an extra line
Inner Left Bicep – black and red birds
Outer Right Wrist – black six lines
Inner Right Wrist – black ring
Right Bicep – black rope-ish design COVER-UP by boat in waves
Inner Right Bicep – black ninja with sword in front of tree
Centre Back – black design

Pictures of Tegan and Sara’s tattoos can be seen here.