Sorry if you weren’t there, but the late ’90s and early 2000s were fantastic. Once P2P was pioneered via Napster, the floodgates opened and the world of music sharing was here to stay. As an artist and a listener, my personal opinion is that we’ve regressed from that time. The problem with the P2P era, admittedly, was that artists were not getting remunerated for their recordings as disruptive tech eagerly pulled down the bloated major-label system. But, well, we’re still not getting paid that much anyway.
The complicated squiggles you see in real-world string vibrations are the mathematical sum of all these different harmonics. Each harmonic produces a different pitch, so when you play a note, you’re actually hearing many different pitches at once. It’s possible to isolate the different harmonics of a string and hear their individual pitches. Harmonics are very useful for tuning your guitar. They are also the basis of the whole Western tuning system generally.