How it works
Sing it backwards, then flip it
The reverse singing challenge has one trick. If you sing a reversed recording well enough and then reverse your attempt, the two reversals cancel out and you hear the original song again. Reverse Song does the reversing, the replaying and the scoring, so all you have to do is sing.
The challenge, step by step
- Step 1
Record a short line
Open Reverse Song and start a challenge. Pick a song line from the list, take the daily challenge, or sing any line of your own. Recording stops by itself after 15 seconds; a short, steady line of four to eight seconds is the easiest place to start.
- Step 2
Listen to it reversed
The app plays your line backwards straight away. Replay it as often as you like, and slow it to 0.75× or 0.5× while you learn the strange new sounds. Headphones help you hear the detail.
- Step 3
Sing what you hear
Record your attempt at the reversed line, copying its sounds, its melody and its pace as closely as you can. You are singing backwards, so it will feel like nonsense. That is expected.
- Step 4
Hear it flipped and get your score
Reverse Song reverses your attempt back to forwards and plays it. If you copied the reversed line well, you hear something close to the original song. The app scores the attempt out of 100 for melody and timing.
How the score is worked out
The score compares your flipped attempt with the original line. Melody counts for 60% and timing for 40%. Melody ignores which octave you sing in, so a deep voice copying a high line isn't penalised. The app scores sound, not words or voice quality.
Read the full explanation of scoring, including what it can't judge.
More in the app
Beyond the challenge
Daily challenge
One song line per day, the same for everyone, picked from the date. It changes at local midnight. Sing it on consecutive days to build a streak.
Song lines
Traditional and public-domain songs in Easy, Medium and Hard. Your highest score for each song is kept. See the full list on the songs page.
Quick Reverse
No challenge, no score: record anything and hear it backwards straight away, or open an audio file from your phone. Every take is saved to your library.
Library and player
Play any clip forwards or reversed. Change speed and pitch with the sliders, try Chipmunk and Deep voice, or turn a clip into a challenge.
Share
Export a vertical video with an animated waveform and your score, or just the audio. Save it to your phone or send it from the share sheet.
Challenge a friend
Pick a recent clip and send it reversed, with a link to the app. Can they sing it back?
What you need
- An Android phone running Android 8.0 or newer.
- Microphone permission, asked the first time you record. Without it the app can still play and reverse audio files you import.
- A quiet room. Background noise and music make your attempt harder to score.
- Optional: headphones, so the reversed line doesn't leak into your recording.
Try a line
Start with an Easy song like "Amazing Grace" at 0.75× and see what you score.