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MUS (.mus)

.mus file signature | application/octet-stream

IFFSimple Musical Score

Safe

Magic Bytes

Offset 0
46 4F 52 4D 53 4D 55 53

Sources: Wikipedia

All Known Signatures

2 signature variants are documented for .mus files across multiple sources.

Hex Signature Offset Sources
46 4F 52 4D 53 4D 55 53 0 Wikipedia
46 4F 52 4D 43 4D 55 53 0 Wikipedia

Extension

.mus

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .mus files in Python

Python
def is_mus(file_path: str) -> bool:
    """Check if file is a valid MUS by magic bytes."""
    signature = bytes([0x46, 0x4F, 0x52, 0x4D, 0x53, 0x4D, 0x55, 0x53])
    with open(file_path, "rb") as f:
        return f.read(8) == signature

How to validate .mus files in Node.js

Node.js
function isMUS(buffer: Buffer): boolean {
  const signature = Buffer.from([0x46, 0x4F, 0x52, 0x4D, 0x53, 0x4D, 0x55, 0x53]);
  return buffer.subarray(0, 8).equals(signature);
}

How to validate .mus files in Go

Go
func IsMUS(data []byte) bool {
    signature := []byte{0x46, 0x4F, 0x52, 0x4D, 0x53, 0x4D, 0x55, 0x53}
    if len(data) < 8 {
        return false
    }
    return bytes.Equal(data[:8], signature)
}

API Endpoint

GET /api/v1/mus
curl https://filesignature.org/api/v1/mus

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .mus file?

A .mus file is a MUS file. IFFSimple Musical Score

What are the magic bytes for .mus files?

The magic bytes for MUS files are 46 4F 52 4D 53 4D 55 53 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .mus file?

To validate a .mus file, read the first bytes of the file and compare them against the known magic bytes (46 4F 52 4D 53 4D 55 53) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .mus files?

There is no officially registered MIME type for .mus files. Systems typically use application/octet-stream as a generic fallback when handling this format.

Is it safe to open .mus files?

MUS (.mus) files are generally safe to open. They are classified as low risk because they primarily contain data rather than executable code. However, always ensure files come from a trusted source.