MIDI Editing

The Piano Roll

The Piano Roll displays MIDI notes as horizontal bars on a grid. Pitch runs vertically (low notes at the bottom, high notes at the top, with a keyboard strip along the left edge). Time runs horizontally. Each bar represents a note — its position is where it starts, its length is how long it sustains, and its color indicates velocity (how hard it was played).

Click a note to select it. Drag it up or down to change its pitch, left or right to change its position in time. Drag the right edge of a note to change its length. These are the basic moves, and most MIDI editing is some variation of them.

Zoom and Navigation

The Piano Roll has its own zoom controls independent of the main Tracks area. Pinch to zoom on a trackpad, or use Option-scroll to zoom horizontally and Option-Shift-scroll to zoom vertically. The vertical zoom matters — spreading the pitch axis out makes it easier to place notes precisely, especially when you are working within a narrow range.

Velocity

Velocity determines how hard a note is struck. In most instruments, higher velocity means louder and brighter. Lower velocity means softer and darker. Velocity is the primary way MIDI performances convey dynamics — the difference between a gentle chord and a hammered one.

Reading Velocity

In the Piano Roll, velocity is encoded in note color. Bright, warm colors (reds, oranges) indicate high velocity. Cooler, darker colors (blues, purples) indicate low velocity. You can read the dynamics of a performance at a glance from the color gradient across the notes.

Below the Piano Roll grid, the velocity lane shows each note’s velocity as a vertical bar. Taller bars mean higher velocity. This gives you a second visual representation — the color tells you the story, the bars let you edit precisely.

Editing Velocity

Three ways to change velocity:

Drag in the velocity lane. Click and drag a velocity bar up or down. Hold Shift to constrain horizontal movement and edit multiple bars in a sweep — drag across a group of notes and they all adjust proportionally.

The Velocity tool. Select it from the tool menu (or assign it as your third tool in the toolbar). With the Velocity tool active, click a note in the Piano Roll grid and drag up or down. The note’s velocity changes as you drag. This is faster than switching to the velocity lane when you just need to tweak one or two notes.

The Inspector. Select one or more notes. The Inspector shows their velocity values numerically. Type a new number to set an exact value. When multiple notes are selected, the value you type applies to all of them — or you can use the relative adjustment (+/- buttons) to shift them all by the same amount while preserving their differences.

Selecting Notes

Beyond click-to-select and Shift-click for multiple selection, the Piano Roll has specialized selection commands that save real time on dense parts.

Select Top Note and Select Bottom Note — when you have a chord selected or a cluster of overlapping notes, these commands isolate the highest or lowest pitch. Useful for pulling a melody out of a chord voicing, or selecting just the bass note of a left-hand piano part. Assign key commands to these if you work with chords regularly.

Select All Notes of Same Pitch — click a key on the piano keyboard strip along the left edge. Every note at that pitch in the visible region gets selected. Fast way to adjust all the kick drum hits, or every instance of a particular note in a melodic part.

Marquee selection — drag a rectangle in the Piano Roll to select everything inside it. Notes that are partially inside the rectangle get selected in full.

Force Legato

Force Legato extends each selected note so it reaches the beginning of the next note, closing any gaps between them. The result is a smooth, connected passage with no silence between notes.

This is useful for pad parts, string lines, or any sustained sound where gaps between notes produce audible dropouts. It is also useful after quantizing — quantize can sometimes shorten notes or create gaps as a side effect, and Force Legato cleans those up in one step.

Select the notes you want to connect, invoke Force Legato, and the gaps close. If notes already overlap, Force Legato trims them back so each note ends exactly where the next one begins.

Region Delay

Region delay shifts the playback timing of an entire MIDI region forward or backward without moving the region on the timeline. The region stays where it is visually — but its notes play slightly early or slightly late.

Find it in the Inspector under the region parameters. The value is in ticks (positive numbers delay playback, negative numbers push it earlier).

Why use this instead of just moving the region? Because region delay is non-destructive and adjustable. You can dial in a few ticks of delay on a bass part to make it sit slightly behind the beat — giving it a heavier, more relaxed feel — without disturbing its position in the arrangement. Change your mind later and reset it to zero.

This is a feel adjustment, not a timing correction. Small values (5-15 ticks) create subtle pocket shifts. Large values move the part noticeably off the grid and usually sound wrong. The goal is to make something feel different, not sound displaced.

Quantize and Auto-Quantize

Quantize in the MIDI context works from the Inspector, covered briefly in earlier chapters. Select a MIDI region, choose a quantize value (1/8, 1/16, etc.), and note start positions snap to the grid. Quantize Strength controls how aggressively — 100% locks everything to the grid, lower values pull notes partway there.

Auto-Quantize applies the current quantize setting to notes as they are recorded. Enable it before recording and every note snaps to the grid the moment it lands. This is useful when you want a tight, mechanical feel and do not plan to humanize the part later. It can also be a crutch — some students leave it on permanently and never develop a sense of why certain parts benefit from imperfect timing. Use it deliberately.

The quantize setting on the region is non-destructive. You can change or remove it at any time. If you want to make it permanent — bake the quantized positions into the actual MIDI data — use Functions > MIDI > Lock SMPTE Position or Normalize Region Parameters from the MIDI Functions menu.

MIDI Draw

Below the Piano Roll grid, you can draw and edit continuous controller (CC) data — mod wheel, expression, sustain pedal, pitch bend, and any other MIDI controller.

Click the disclosure triangle at the bottom of the Piano Roll to reveal the MIDI Draw area. Use the dropdown to choose which controller to display. The data appears as a series of points connected by lines, and you can draw new values with the pencil tool or edit existing ones by dragging.

Common uses:

• Mod wheel (CC 1) — automate filter sweeps, vibrato intensity, or crossfade between articulations on orchestral instruments
• Expression (CC 11) — volume shaping that preserves the velocity dynamics of individual notes
• Sustain pedal (CC 64) — add or remove pedal marks after recording
• Pitch bend — draw pitch slides, bends, and scoops

MIDI Draw gives you automation-level control over parameters that are part of the MIDI data rather than the channel strip. If your instrument responds to CC data (most do), this is where you shape those responses after the performance is recorded.

A Note on Fades

Fades and fade zones are an important audio editing tool — you can apply them to many regions at once, which makes them efficient for cleaning up transitions across an entire arrangement. Fade click zones need to be enabled in Preferences (look under General > Editing), but fades can also be typed manually in the Inspector by entering precise values for fade-in, fade-out, and crossfade lengths. One thing to know: fades do not work on MIDI regions. They are strictly an audio editing feature. If you need a volume shape on a MIDI region, use automation or velocity editing instead.

The Score Editor

Logic includes a full Score Editor that displays MIDI data as traditional music notation — notes on a staff with clefs, time signatures, dynamics, and articulation marks.

Most students in this course never open it. If you read music fluently and prefer working with notation, it is there — and it is surprisingly capable. You can enter notes directly on the staff, print parts, and export notation. But the Piano Roll is the primary MIDI editing environment for production work, and everything in this chapter applies there.

If you do explore the Score Editor, know that it displays the same MIDI data as the Piano Roll — just in a different visual format. Edits in one are reflected in the other.

What to Practice

• Open a MIDI region in the Piano Roll. Look at the velocity colors — can you see which notes were played harder? Switch to the velocity lane and compare the bar heights to the note colors. Edit a few velocity values and listen to the dynamics change.
• Record a chord progression. Use Select Top Note to isolate the melody notes from the chords. Try adjusting their velocity independently from the rest of the voicing.
• Record a legato passage — a smooth string line or pad part — and leave small gaps between notes. Select all the notes and invoke Force Legato. Listen to the gaps close.
• Try region delay: record a simple bass line alongside a drum loop. In the Inspector, set the region delay to +10 ticks. Listen to how the bass sits slightly behind the beat. Set it to -10 ticks and hear the opposite effect — the bass pushing ahead. Reset to zero and compare.
• Open the MIDI Draw area and select mod wheel (CC 1). Draw a gradual curve from low to high across a sustained note. If your instrument responds to the mod wheel, you will hear the parameter change in real time during playback.

Commands in This Chapter