Hex for MIDI Channel 1 Note On Command

This article explains the hexadecimal value used to trigger a Note On message on MIDI Channel 1. It details the exact hex code required, breaks down the byte structure behind MIDI channel messaging, and illustrates how subsequent data bytes define the pitch and velocity of the triggered note.

The hexadecimal number that identifies a Note On command on MIDI Channel 1 is 90 (commonly written as 0x90 in programming).

In the MIDI 1.0 specification, channel voice messages begin with a status byte comprised of two hexadecimal characters (nibbles):

• The Command Nibble (First Digit): The digit 9 represents the "Note On" message type.
• The Channel Nibble (Second Digit): MIDI channels are zero-indexed internally, ranging from 0 to F (representing channels 1 through 16). Therefore, Channel 1 is represented by 0.

Combining the command 9 with channel index 0 results in the status byte 90.

A complete standard MIDI Note On event consists of three bytes:

1. Status Byte (90): Initiates a Note On command on Channel 1.
2. Data Byte 1 (Pitch): A hex value ranging from 00 to 7F (0–127 in decimal) specifying the note number, where middle C (C4) is typically 3C (60 in decimal).
3. Data Byte 2 (Velocity): A hex value ranging from 00 to 7F (0–127 in decimal) specifying how hard the note was struck.

If a 90 status byte is transmitted with a velocity value of 00, standard MIDI protocol interprets this as a Note Off command for that specific pitch, allowing synthesizers and sequencers to conserve data bandwidth via running status.