pat2midi

A command-line tool to convert drum pattern text files (.pat) to MIDI files. Based on the file format from the drum-patterns repository.

Basic Usage

Convert a single pattern file to MIDI:

deno --allow-read --allow-write pat2midi.ts examples/example.pat

Convert a pattern file with custom velocity settings:

deno --allow-read --allow-write pat2midi.ts examples/named.pat --accentVelocity 100 --normalVelocity 80

Convert all pattern files in a directory:

deno --allow-read --allow-write pat2midi.ts examples

Debug mode outputs MIDI file contents as JSON:

deno --allow-read --allow-write pat2midi.ts examples/example.pat --debug

Pattern File Format (.pat)

Pattern files use a simple text format where each line represents a drum instrument:

42 x---x---x---x---
38 ----x-------x---
36 x-------x-x-----
AC ----x-------x---

Each line contains:

• A MIDI note number or drum name (e.g., 42 or CH)
• A pattern using 'x' (hit) and '-' (silence)
• Optional 'AC' line defining accents

Using Drum Names

Standard drum names can replace MIDI numbers:

CH --x---x---x--xx-
CP ----x-------x---
BD x---x---x---x---
AC ----x-------x-x-

Supported Drum Names:

Name	Description	MIDI Note
BD	Bass Drum	36
RS	Rim Shot	37
SD	Snare Drum	38
CP	Clap	39
CH	Closed Hi-hat	42
LT	Low Tom	43
OH	Open Hi-hat	46
MT	Mid Tom	47
CY	Crash Cymbal	49
HT	High Tom	50
CB	Cowbell	56

Background

Inspired by drum-machine-patterns, drum-patterns and René-Pierre Bardet's book 200 Drum Machine Patterns. Created to provide ready-to-use MIDI drum patterns.