What Is PPQN in MIDI? 960 PPQN vs 24 PPQN Explained
In digital music production, PPQN (Pulses Per Quarter Note) defines the timing resolution of a MIDI sequencer, determining how accurately note events, automation, and micro-timing can be captured and played back. While legacy hardware systems operated at a coarse 24 PPQN standard, modern Digital Audio Workstations (DAWs) typically use 960 PPQN or higher. This guide explains what PPQN is, breaks down the technical differences between 24 and 960 PPQN, and explores how this evolution in resolution impacts musical feel, expression, and workflow.
What Is PPQN?
PPQN, also referred to as Ticks Per Quarter Note (TPQN), measures the internal clock resolution of a sequencer. It specifies the number of discrete clock ticks into which a single quarter note is divided.
Because digital sequencers operate on discrete steps rather than a continuous analog timeline, every MIDI event—such as a note-on message, pitch bend, or control change (CC)—must snap to the nearest tick. A higher PPQN value means smaller time intervals between ticks, allowing for higher temporal precision and a more accurate representation of unquantized, human performance.
Legacy 24 PPQN: The Vintage Standard
The 24 PPQN standard originated in the early days of electronic music synchronization, most notably utilized in Roland's DIN Sync (Sync24) standard and early MIDI hardware from the 1980s, such as the TR-808 and TR-909 drum machines.
Under a 24 PPQN system, a quarter note contains exactly 24 ticks:
- A sixteenth note consists of only 6 ticks (\(24 / 4\)).
- A thirty-second note consists of just 3 ticks (\(24 / 8\)).
- A sixty-fourth note cannot be mathematically represented without falling between ticks.
Because the grid is so coarse, subtle human micro-timing is completely erased upon recording or playback. Any note played slightly off-beat is rounded to the nearest tick, forcing performances into a rigid structure. However, this limitation gave birth to the signature "groove" and swing characteristics of early house, hip-hop, and techno, as swing algorithms could only shift notes by coarse, fixed intervals.
Modern 960 PPQN: High-Definition Sequencing
Modern DAWs—such as Pro Tools, Logic Pro, and Cubase—standardized around 960 PPQN, which provides 40 times the resolution of 24 PPQN hardware.
Under a 960 PPQN system:
- A sixteenth note consists of 240 ticks (\(960 / 4\)).
- A thirty-second note consists of 120 ticks (\(960 / 8\)).
- Even a 128th note contains 30 distinct ticks.
At 960 PPQN, the time difference between adjacent ticks at 120 BPM is approximately 0.52 milliseconds. Because the human ear generally cannot perceive timing differences smaller than 5 to 10 milliseconds, a 960 PPQN resolution effectively functions as a continuous, analog-like timeline.
Key Comparisons: 24 PPQN vs. 960 PPQN
| Feature | Legacy 24 PPQN | Modern 960 PPQN |
|---|---|---|
| Ticks per 16th Note | 6 ticks | 240 ticks |
| Human Feel | Coarse, heavily quantized | Fluid, captures rubato and micro-timing |
| Continuous Data (CC) | Audible "stepping" or zipper noise | Smooth automation and pitch bends |
| Swing Flexibility | Limited to fixed mathematical steps | Near-infinite, customizable swing percentages |
| Primary Use Case | Vintage hardware, retro aesthetics | Professional modern music production |
Why PPQN Matters in Production
The primary sonic consequence of PPQN is the balance between machine-like rigidity and human nuance. When recording a live performance via a MIDI keyboard or electronic drum kit into a 960 PPQN environment, every slight push and pull of the beat is accurately preserved. In contrast, running that same performance through a 24 PPQN engine flattens the performance into a robotic cadence.
Furthermore, PPQN drastically affects continuous controller data. Modulating a filter cutoff or pitch bend wheel generates a stream of MIDI messages. At 24 PPQN, the low density of updates produces an audible stepping artifact known as "zipper noise." At 960 PPQN, the parameter changes occur rapidly enough to create seamless, imperceptible transitions.