Barline: Slow Down Music

Slow down music you're learning by ear and loop the exact bars you need, without changing the key. Import a track you own and Barline maps its bars and beats on your phone, so a loop starts where the music actually turns over.

MAPPED ON THE PHONE, ONCE

The first time you import a song, Apple's on-device music analysis finds its beats, bar lines, sections and key. The audio never leaves the phone, there is no account, and the map is saved, so the song opens instantly after that.

LOOPS THAT LAND ON THE BAR

Tap a section to loop it, or drag across the waveform and the selection snaps to bar lines as you go. The loop goes round with no gap at the seam and counts the repeats. Rather go by ear? Tap Mark start and Mark end as the phrase goes by. If a phrase starts a beat early, nudge either edge a beat at a time.

SLOW IT DOWN, THEN CLIMB BACK UP

Speed from 40% to 120% without changing the key, and pitch up to twelve semitones either way without changing the speed. Turn on the practice ramp and the loop gets a little faster every few repeats until it reaches full tempo.

KEEP THE LOOPS THAT MATTER

A saved loop keeps its bars, speed, pitch and ramp. Markers drop at the playhead so you can jump straight back to the bit you keep losing, and every song has room for notes. There is a count-in, and Lock Screen controls for when the phone is on the stand and the instrument is in your hands.

IF THE DOWNBEAT IS OUT, MOVE IT

Live recordings and rubato catch out every beat tracker sometimes. Choose Correct the downbeat, tap on two or three beats you are sure are the one, and the whole grid moves, with every section and saved loop following it.

WHAT IT COSTS

Barline is free to download. Importing and practicing songs needs Barline Unlimited, a subscription, and new subscribers get the first week free on either plan; canceling at least 24 hours before it ends costs nothing. The App Store shows the price in your own currency before you confirm. If the subscription ever ends, nothing is deleted: your songs, loops and notes stay on the phone and open again when you subscribe.

SUBSCRIPTION DETAILS

Barline Unlimited Monthly: 1 month, renewing every month.
Barline Unlimited Yearly: 1 year, renewing every year.
Either plan unlocks importing and opening songs, with every feature above. New subscribers get the first week free; unless canceled at least 24 hours before it ends, the subscription starts when the week is up. Payment is charged to your Apple Account when you confirm, or when the free week ends. The subscription renews automatically unless you turn it off at least 24 hours before the end of the current period. Manage or cancel it in Settings › your name › Subscriptions.

Terms of use: https://mirentha.com/apps/barline/terms/
Privacy policy: https://mirentha.com/apps/barline/privacy/

REQUIREMENTS

iPhone with iOS 27 or later. Imports MP3, M4A, WAV, AIFF and FLAC files you have the right to use, from the Files app or iCloud Drive. Streamed Apple Music and Spotify tracks are copy-protected and can't be imported.