It's day 14,611

Here's what we sang:
(Who sang what is from my memory, which means it's probably not accurate)

All  // Star Spangled Banner // Cher (I previewed all four version and the Cher one was the winner)
Me // Flowers In Your Hair // The Lumineers
Matt // Personal Jesus // Depeche Mode 
Kelly // LIVIN' ON A PRAYER // Bon Jovi
Jimmy // Tie A Yellow Ribbon // Tony Orlando
Burt // The Letter // Joe Cocker
Someone // Sunshine Superman // Donovan
Jeff // The Witch Doctor // David Seville
Hafidha // I Don't Want To Be // Gavin DeGraw
Jeff  // My Sharona // The Knack
Ameena // Just A Girl // No Doubt
Deborah and me // Galileo // Indigo Girls
Allegra //  Don't Stop Believin'  // Journey
Andrew //  Touch Me // The Doors
MaryAnn & Me // Baby It's Cold Outside // Glee Cast
Matt & Tara // Shake It Off // Taylor Swift
Deobrah & ? // Jack And Diane // John Mellencamp
Chris // Folsom Prison Blues // Johnny Cash
Burt  // New Shoes // Paolo Nutini
Devon // Night Moves // Bob Seger
Olivia // Boogie Shoes // K.C. & The Sunshine Band
Tiffany & crew // Gettin' Jiggy Wit It // Will Smith
Tara and me // Danny's Song // Loggins & Messina
Mark // Taxi // Harry Chapin
Deborah, Burt (and everyone, really) // Bohemian Rhapsody // Queen
John // Wagon Wheel // Old Crow Medicine Show
MaryAnn // Strong Enough // Cher
Cindy & Me (sung like in high school) // You Shook Me All Night Long  // AC/DC
Someone // I Can't Go For That (No Can Do) // Hall & Oates
Tiffany & Tim //  Build Me Up Buttercup // The Foundations
Chris // Town Without Pity // Gene Pitney
Danielle, Deborah & Allegra // Jessie's Girl // Rick Springfield
Burt & Laurie // Endless Love // Lionel Richie & Diana Ross 
Devon  // In The Ghetto // Elvis Presley
Tiffany, Olivia, MaryAnn, Philip & Branka  // Wannabe // Spice Girls
Matt and Me // My Eyes // Dr. Horrible's Sing Along Blog
MaryAnn & Philip // The Girl Is Mine // Michael Jackson & Paul McCartney
Mark // Moondance // Van Morrison
Danielle & Deborah // Harper Valley P.T.A. // Jeannie C. Riley
Jeff Norton // One Week // Barenaked Ladies
Cindy // Wake Me Up Before You Go-Go // Wham! 
Allegra & ? // Don't Stop // Fleetwood Mac
Allegra, Matt, Tiffany & Olivia // Baby Got Back // Jonathan Coulton

Regular commenter Jan took a bunch of great photos.  Here is one that captures the flavor of the evening.  It's a moment in the excellent rendition of "Jessie's Girl" which had the best karaoke typo of the evening: "the point is mute" (moot).