What Is a MIDI File? A Beginner's Guide

Unlike an MP3 or WAV file, a MIDI file doesn't contain recorded audio. Instead, it stores musical instructions that tell software or digital instruments which notes to play and when to play them.

Think of a MIDI file as digital sheet music for a computer.

Instead of storing the sound of a piano, guitar, or violin, it stores information such as:

• Which notes are played
• When each note starts
• How long each note lasts
• How hard each note is played
• Which instrument should play the notes

When a MIDI file is opened, your computer or music software uses those instructions to play the music using virtual instruments or sound libraries.

Because MIDI contains note data instead of recorded audio, it's incredibly flexible.

Musicians can edit mistakes without re-recording a performance, change instruments with a few clicks, adjust the tempo without affecting sound quality, and experiment with new arrangements.

That's why MIDI has remained a standard format in music production for decades.

You may also come across the term General MIDI.

General MIDI is a standard that assigns specific instruments to program numbers so that MIDI files sound reasonably consistent across different devices.

For example, one instrument number always represents an acoustic piano, while another represents a violin or electric bass.

Many music programs also support General MIDI soundfonts or virtual instruments, allowing you to choose higher-quality sounds while keeping the same MIDI performance.

Although they're closely related, MIDI files and sheet music serve different purposes.

Sheet music is designed for musicians to read while performing.

MIDI is designed for computers and music software. It provides far more editing flexibility but isn't as practical for learning a song at the piano.

Many musicians like having both formats available: sheet music for practicing and MIDI for editing, arranging, or composing.