What Is a Piano Roll? How to Read and Write MIDI in a DAW

What is a piano roll?

A piano roll is the MIDI editor in a DAW: a grid where pitch runs vertically, time runs horizontally, and every note is a bar you can draw, move, stretch or delete. It does not hold audio. It holds instructions that tell an instrument which note to play, when, for how long and how hard.

The name is literal. Image-Line's manual points out that its piano roll works on the same principle as the paper rolls that once automated player pianos^[1]. Apple describes Logic's version as color-coded bars in a time grid, with a keyboard along the left edge as a pitch reference^[2]. Every DAW has one, even if Ableton calls it the MIDI Note Editor^[3]. If MIDI itself is new to you, read the MIDI basics tutorial first.

How do you read a piano roll grid?

Read a piano roll like a graph: higher bars are higher notes, bars further right happen later, and longer bars last longer. The ruler along the top counts bars and beats, and the grid lines inside each bar come from your snap setting.

In FL Studio, the number on the top ruler marks bars, and the finer grid inside each bar is set by the snap control^[1]. Change snap and you change where new notes can land.

• Keyboard (pitch axis) The piano keys on the left. Each row is one semitone, and C notes are usually labeled so you can find octaves quickly.
• Ruler (time axis) Bars and beats across the top. In 4/4, one bar holds four beats.
• Grid or snap The subdivision notes lock to, such as 1/8 or 1/16. Finer grids allow faster rhythms.
• Note bars The start of a bar is when the note plays, its vertical position is the pitch, and its length is how long it is held.
• Velocity lane A strip below or inside the notes showing how hard each note is played.

What do note length and velocity control?

Note length sets how long the instrument holds a note, and velocity sets how hard the note is struck, which usually means how loud it is. Together with pitch and position, they are the four values every MIDI note carries.

Apple's velocity reference explains that velocity indicates how hard the key was struck, usually corresponds to loudness, and runs from 0 to 127 with 127 the loudest; it can also drive other parameters such as filter cutoff^[4]. That 0 to 127 range is the MIDI 1.0 standard. MIDI 2.0 raises note velocity to 16-bit resolution, 0 to 65,535, for finer dynamics on instruments that support it^[5].

When length matters and when it does not

Length matters for sustained sounds like pads, strings and 808s, where a longer bar means a longer note. It often matters little for drums loaded in one-shot mode, because the sampler plays the whole hit regardless of how long the MIDI note is. If an 808 cuts off too early or rings into the next note, check note length first.

Default values are a clue

Logic creates new notes with the length, velocity and channel of the last note you edited; a new project starts at 240 ticks, velocity 80 and MIDI channel 1^[6]. Many beginners never change the default, which is why their programmed parts sound flat. Vary velocity on hats, ghost notes and repeated chords to make parts breathe.

What does quantize do in a piano roll?

Quantize moves note starts to the nearest grid line, so notes you played slightly early or late land exactly in time. Strength and swing settings let you correct timing partway or add a shuffled feel instead.

Logic's Time Quantize works non-destructively for playback, so the original timing is never lost, and it offers Strength and Swing sliders^[7]. In FL Studio, Quick quantize uses the global snap setting, while the full Quantize command opens a settings dialog^[8]. Ableton's Quantize command uses the settings in its Quantize MIDI tool^[3].

Full quantize is right for most programmed drums and basslines. For played keys or live-feel drums, try 50 to 75 percent strength first so the part tightens without turning robotic. The guide to quantizing drums without killing the groove goes deeper on swing and groove templates.

Piano roll tools in FL Studio, Ableton Live and Logic Pro

The three major beatmaking DAWs share the same core tools: draw, select, quantize and a velocity editor. Only the names and shortcuts change.

FL Studio also shows ghost notes from other channels in the same pattern, which helps you write a bassline against a chord part^[1]. Once the basics feel natural, the advanced FL Studio piano roll techniques article covers chopping, strumming and arpeggio tools.

How do you write your first melody in the piano roll?

Pick a scale, set a grid, draw a short phrase, then edit length and velocity until it sounds played rather than typed. Keep the first idea to one or two bars.

1. Load an instrument
   Put a simple piano, pluck or bell on a MIDI or instrument track. Clear sounds make timing and pitch mistakes obvious.
2. Choose a key and scale
   Start in A minor, which uses only the white keys. Turn on your DAW's scale snap or highlighting if it has one.
3. Set the grid to 1/8
   Eighth notes are easy to hear and hard to overcrowd. Move to 1/16 later for faster rhythms.
4. Draw a two-bar phrase
   Write four to six notes, end the phrase on the root note A, and leave at least one gap so the melody can breathe.
5. Adjust lengths
   Stretch the last note of each phrase so it rings, and shorten notes that blur into the next one.
6. Shape velocity
   Accent the first beat of each bar around 100 to 110 and drop passing notes to around 70 to 90 as a starting point.
7. Loop, copy and vary
   Loop the two bars, duplicate them, and change only the last two notes of the copy to create a call and response.

Common piano roll mistakes beginners make

Most beginner problems in the piano roll come from leaving every value at its default. These are the fixes worth learning first.

• Every note at the same velocity Programmed parts sound mechanical. Vary velocity by 10 to 30 steps on repeated notes.
• Overlapping notes on mono sounds Overlaps can trigger glide or cut notes short on a mono bass. Trim note ends unless you want the slide.
• Grid too fine Writing melodies on a 1/32 grid invites clutter. Start coarse and refine.
• Quantizing everything to 100 percent Hard quantize removes the push and pull of played parts. Use partial strength or swing.
• Ignoring the key Wrong notes are easy to draw by accident. Scale snap or highlighting prevents most of them, and a chord progression guide helps you choose notes that fit.