Autoscroll

Autoscroll

The Autoscroll feature in JustChords automatically scrolls a song's chords and lyrics from top to bottom while you play, so you can keep your hands on your instrument instead of on the screen.

How it works

Autoscroll is available in Scrolling view mode. When activated, the song content moves at a constant speed from the start of the song to the end. The scroll is driven by a duration value (in seconds) — JustChords spreads the entire song's content evenly across that duration using a linear animation.

You start and stop autoscroll from the floating menu in the song viewer using the chevron-down button. While autoscroll is running, you can fine-tune the speed in real time:

• + button — slow down (adds 10 seconds to the remaining duration)
• − button — speed up (subtracts 10 seconds from the remaining duration)
• Long-press either button for continuous adjustment

Any changes made while scrolling are saved back to the song's duration when you exit the song.

Duration: song-specific vs. global

JustChords resolves which duration to use in this order:

1. Song duration — if the song has its own duration set (for example, the actual song length in seconds), that value is used.
2. Global default duration — if the song has no duration set (or it is 0), Autoscroll falls back to the Default song duration configured in Settings → Autoscroll.

This means you can configure a reasonable default for all your songs once, and only override it on individual songs that need a different pace.

Trigger options

In Settings → Autoscroll you can configure when Autoscroll should start automatically:

• On song appear, with a configurable delay (1–10 seconds)
• When audio or the metronome starts playing

You can also enable Center Autoscroll to keep the currently scrolling region vertically centered on screen.

ScrollByBeats override

When chord beats are enabled and visible in the song, and the MIDI transport is running, the timed Autoscroll is overridden by ScrollByBeats behavior. In this mode the Autoscroll button is hidden — scrolling is no longer driven by a duration, but by the actual beats coming from MIDI.

ScrollByBeats activates when all of these are true:

• MIDI is enabled in Settings
• The MIDI transport is currently running
• Chord beats are shown in the song (not hidden)

Why beat-based scrolling is more accurate

Timed Autoscroll is an approximation: it assumes the song is played at a steady pace matching the configured duration. If you slow down, speed up, repeat a section, or pause, the scroll position will drift from where you actually are in the song.

ScrollByBeats is event-driven. Each MIDI beat advances the current section/part, so the view always reflects exactly where the song is right now, synchronized to the MIDI clock or host transport. It even jumps ahead to the next section a couple of beats before the current one ends, or loops the current section when appropriate.

Because it follows the real musical timeline rather than wall-clock time, ScrollByBeats stays in sync regardless of tempo changes, repeats, or pauses — which is why JustChords prefers it whenever chord beats are available.

Summary

• Timed Autoscroll — linear scroll across the song's duration, or the global default if none is set. Adjustable in real time with +/− buttons.
• ScrollByBeats — replaces timed Autoscroll whenever MIDI chord beats are enabled, running, and visible. Advances the view beat-by-beat for accurate synchronization with the actual performance.