Use a tool like 7-Zip or WinRAR to extract "part1.rar"; it will automatically pull data from part 4 and other segments.

💡 Ensure you have all preceding parts (1 through 3) before trying to open part 4, or the extraction will fail. If you'd like more help with this, tell me: Do you have all the other parts of the archive?

Bundles of 10 songs released by genre (e.g., Chill, Pop, or Rock).

The "part4" designation indicates this is one piece of a multi-part compressed archive. To access the content, you generally need all parts (part1, part2, etc.) in the same folder.

Inside, you will typically find .pak and .sig files for individual songs.