Reverse Singing Challenge: How to Do It on iPhone (Free)

The short answer

The reverse singing challenge has four steps: record a short line, play it backwards, record yourself copying the backwards gibberish, then play *your* attempt backwards. If you copied it well, the original line comes back out, slightly drunk. If you did not, you get something far funnier.

The only hard part is the flipping. You can do it in any audio editor, but that means exporting, reversing and re-importing twice per turn, which kills the fun at a party.

Trending Music has the whole loop built in as a free tool called Reverse Singing. Open the Social tab and tap the Reverse Singing tile under Explore, or go to Library → Tools → Games → Reverse Singing. Then:

1. Tap the mic and sing or say a short phrase. Tap again to stop (it stops itself at 15 seconds). 2. The app plays it back backwards straight away. Listen until you can copy it. 3. Tap the mic again and record your attempt at the backwards version. 4. The app flips your attempt and plays the reveal. Everyone finds out.

The rest of this guide is about the part no app can do for you: actually getting good at it.

Why the reveal sounds so strange

If you could copy the backwards clip perfectly, the reveal would be a perfect copy of the original. Nobody can, and the reason is the whole joke.

Sounds are not symmetrical. A "t" or a "k" is a sharp burst that fades; reversed, it becomes a sound that swells up out of nothing and stops dead, which the human mouth is not built to produce. An "s" at the end of a word turns into a hiss at the *start* of the reversed word. Vowels survive the flip much better, because a held "ah" sounds roughly the same in either direction.

So the reveal comes back with the vowels mostly intact and the consonants smeared. That is why a sung line works better than a spoken one: melody and long vowels carry through, and the listener's brain fills in the rest.

Step by step in Trending Music

First time only: iOS asks for microphone access. Allow it. If you tapped "Don't Allow" earlier, the app shows a Microphone needed prompt with an Open Settings button that takes you straight to the switch.

Step 1, the original. Tap the big mic button and sing your line. A timer counts up while you record. Tap again to stop, or let it run to the 15-second cap, where it stops on its own.

Step 2, study the backwards version. As soon as you stop, the backwards clip plays. You now get three controls:

- Play it backwards replays the reversed clip as many times as you like. - Hear the original plays your first recording the right way round. - A Speed slider slows playback from 1.0× down to 0.5×.

Step 3, your attempt. When you think you have it, tap the mic (it now says Record your attempt) and perform the backwards gibberish at normal speed.

Step 4, the reveal. The app reverses your attempt and plays it. Play the reveal replays it, Share sends it on, and Start over clears everything for a new phrase.

Not happy? Tap the mic again from the reveal screen (Record again) and you get another attempt at the same phrase, without having to re-record the original.

How to pick a line you can actually win with

Most failed attempts are lost at step one, by choosing the wrong phrase.

Keep it to two to four seconds. The 15-second limit is a ceiling, not a target. A backwards clip longer than a few seconds is nearly impossible to memorise, and a short one keeps the turn moving.

Pick a line everyone knows. The reveal only lands if the room recognises it. "Happy birthday to you" or a famous chorus hook beats a clever obscure lyric every time, because half the fun is the second where everyone suddenly hears it.

Favour long vowels and melody. Singing beats speaking, and a slow, held line beats a fast one. Lines packed with "t", "k", "p" and "s" sounds are the hardest to rebuild.

Record it clearly. Hold the phone close, sing towards its bottom edge where the microphone is, and do it in the quietest corner you can find. Room noise gets reversed too, and it makes the gibberish much harder to copy.

How do you learn the backwards version?

Slow it down with the Speed slider first. At 0.5× the backwards clip stops being noise and turns into separate syllables you can hear clearly.

Then work in chunks: the first two syllables, then the next two, then join them. Write it down phonetically if it helps, however silly it looks ("ooy ot yad-rib ip-pah").

Copy the breaths and the loud bits as well as the sounds. Where the backwards clip swells, you swell.

Before you record, drag the slider back to 1.0×. Your attempt has to be performed at normal speed, and the speed setting also applies to the reveal.

Turning it into a party game

On its own it is a funny thirty seconds. With a group it becomes a proper game, and it needs only one phone.

The guessing version. One person takes the phone into another room and records a well-known line as the original. Everyone else hears only the backwards clip, then takes a turn recording an attempt. The group guesses the original from each reveal, and the host finally plays Hear the original to settle it. Use Record again for each new player so the original stays the same.

The head-to-head version. Two players, same phrase, one attempt each. The room votes on whose reveal sounded closer. Swap who picks the phrase each round.

House rule worth agreeing up front: the original has to be a real line from a song, not something invented. Made-up phrases are unguessable, and the game falls flat.

If the room is more in the mood for guessing songs than singing them, the music games you can play with one phone are the better fit.

What does the Share button actually post?

It makes a vertical 9:16 video: a still card with the words "Reverse Singing" and "Trending Music" on it, with the reveal audio as the soundtrack. It opens the standard iOS share sheet, so you can send it to any app that takes video.

It does not include your face, the backwards clip or the original recording. The version of the trend where people see you pulling faces while you sing backwards is a camera video, and the app does not film you. The simple way to get that is to have a friend film you on a second phone while you play.

Is it free?

Yes. Reverse Singing has no Premium lock and no weekly limit. On the free tier a banner ad sits at the top of the screen; Premium removes it.

Your recordings are made on the phone and nothing is uploaded unless you choose to share the reveal. They are also temporary: close the screen and they are gone, so share the reveal first if it is one to keep.

What happens to the music I was playing?

Recording takes over the phone's audio, so whatever was playing stops when you open Reverse Singing. When you close it, a song or a radio station that was playing picks up again by itself. A podcast does not: you will need to press play on it yourself.

What it will not do

Worth knowing before you promise anyone a performance:

- No scoring. The app does not judge how close you got. The room does. - No camera. As above, the shared video is audio on a still card. - 15 seconds maximum per recording, which is plenty for this game. - No history. Takes disappear when you leave the screen.

If you want a screen that grades you, this is not it. If you want a laugh with whoever is in the room, it does the job with nothing to set up.

Try it tonight

Pick one line everyone knows, keep it under four seconds, and slow the backwards clip right down before you try.

Reverse Singing is free inside Trending Music. Open the Social tab and tap Reverse Singing, or find it under Library → Tools → Games.

Get Trending Music free on the App Store