FLAC (Free Lossless Audio Codec) is the preferred format for music preservation because it reduces file size by 50–70% without discarding a single detail. When you listen to an HQ FLAC version of this track:
True FLAC files provide lossless compression, retaining all data from the original recording. On platforms like YouTube, look for "Remastered" or "1080p" versions to get the highest possible bitrate.
When you compress a Metallica song to 320kbps MP3, you throw away roughly 90% of the audio data. You lose the "breath" between notes. You lose the metallic ring of the ride cymbal. You lose James Hetfield’s vocal rasp decaying into the silence.