Backwards

It's not likely that TMBG are backmasking satanic instructions (They Might Be Giants are not Satanists!*), however, there is some playing with backwards recording and backwards themes.

Backwards singing

Entire song

• Gazing Out Toward - Linnell singing "Quit looking at me" played backwards
• On Earth My Nina - This song is "Thunderbird" sung backwards
• stelluB - This song is "Sapphire Bullets Of Pure Love" sung backwards

Portions

• 25 O'Clock - A portion is played backwards and also slowed down and sped up. It apparently name-checks some of XTC's contemporaries, such as Adam Ant.
• Hearing Aid - The intro appears to be the words "Your Mercy" played backwards, then forwards.
• I'll Sink Manhattan - Message from a NYPD officer played backwards: "'Thanks a lot guys. From the NYPD. We love you.'"
• Subliminal - Part of the chorus turned backwards at the end of the song.
• Which Describes How You're Feeling (Demo) - Halfway through there's a backwards section. Played in reverse, it says, "They Might Be Giants wanted to include a verse about the suffering people of the world, but we couldn't figure out where to put it into the song."

Singing backwards

• Dinner Bell - The listing of body parts ("Shoulder, bicep, elbow, arm. Forearm, thumb, wrist, knuckle, palm. Middle, pinky, index, ring.") was recorded. That tape was played backwards and the Johns learned to imitate that backwards speech phonetically. They then sang that into a tape and reversed that tape. So it ends up forwards.

Pretending to sing backwards

• Best Of Spin The Dial - Flans sings one song (While My Guitar Gently Weeps, by the Beatles) in a backwards sounding voice
• Exploding Invitation
• The 6-30-2006 performance of Fingertips, Flansburgh sings "I don't understand you" in his backwards singing voice
• Hide Away Folk Family - Pretend backwards at the end
• Smells Like Teen Spirit
• Which Describes How You're Feeling - The demo version (above) is actually backwards, but this is just pretending

Backwards music

• Am I Awake? - Backwards marxophone
• Cowtown (1985 Demo 2) - Backwards synth at beginning
• Dollar For Dollar - Most of the instrumental part is played backwards; some reversed moaning by Linnell
• Everything Right Is Wrong (1984 Demo) - Has backwards tambourine samples
• I'm A Coward - Backwards guitar
• Koenigstein - Backwards bass solo and drum track at the end
• Letterbox - Backwards drum machine hits at the beginning
• Mona Lisa - Some backwards instruments
• Operators Are Standing By - Occasional backwards cymbal
• Pop-A-Shot - Some backwards instruments
• Savoy Truffle - A portion of the song includes a backward guitar
• Science Is Real - Backwards piano at the beginning
• S-E-X-X-Y (Radio Edit) - Backwards cymbals
• Wearing A Raincoat - Backwards guitar solo

Backwards as a central theme

• Destination Moon - The chorus describes how to get to the moon, backwards.
• ECNALUBMA - Backwards title, and the music video consists of reversed footage of a parade
• I Palindrome I
• The Neck Rolls Aren't Working - In the final verse involves the narrator noticing time moving backward.
• Z Y X - the alphabet backwards.

Briefly mentioned

• Ana Ng - "And her voice is a backwards record"
• The Bright Side - "Backwards ran your sentences", followed by a reversible verse
• Darling, The Dose - "Time's in reverse"
• Destroy The Past - "Let's go backwards to destroy the past"
• Hypnotist Of Ladies - "Never counted backwards"
• It Said Something - "Speak it in reverse so the babies can see"
• Push Back The Hands - "To move it backward"
• Trouble Awful Devil Evil - "Sweetly as I fall backwards in slow motion and sink into bliss"

Honorable mention

• Can't Keep Johnny Down - The Bees Knees version of the video is played backward.