Without getting too technical, this is about the final stage of music production, the
mastering of a track. This can be traced back some time, even back to old jukeboxes playing 45s where the mastering engineer would be encouraged to make the record louder than any of the others, thus making it stand out more in a crowded bar. The technical limitations of vinyl however kept this in check to some degree. Yet with the rise of the CD over the last 20 odd years, engineers have been pushing the levels of perceived loudness to the technical limits of digital technology.
I've traced this back roughly in digital terms to Electronic's first album, and the same mastering engineer went on to produce Oasis's first 2 albums, flying the flag for a new wave of 'loud and proud' which is persistent today.
What's wrong with loudness I hear you shout?
Nothing... if that's what you like. However, this has been both a commercial tool and a case of engineers simply following suit as they're loath to let other artists have louder records by comparison, especially if a tune appears in a compilation in case it makes theirs seem wimpy, and A&R men and record labels seem to have the engineers by the balls to make it sound how they want because at the end of the day it's also about record sales. Quite simply, many mastering engineers have sold out for the buck.
What's essentially happening is the dynamic (the difference between the loudest and quietest parts of a tune) is being removed by over-compressing, squashing and crushing the music and bringing the whole overall level of the tune up to as loud as it can go. This removes much of the emotion that a natural dynamic can create, and also decreases any warmth in the sound quality, rendering the overall feel sounding quite harsh. This has become so drastic, that even metal fans are complaining that it's too loud. Metallica's
Death Magnetic album was almost the pinnacle of this with many fans complaining about the horrid production and demanding it be re-produced. Yet by some ironic twist, Avril Lavigne is louder than Metallica and Katy Perry is louder than Megadeth!
This also creates problems with radio play. Have you noticed how so much music now on the radio sounds horrible? It's not just because it's generally pop music. The radio station adds it's own compression & other processing to the music as part of its broadcast, meaning any track that has already gone through the extreme mastering process I've outlined above simply ends up more distorted and harsh. It also means that the beginning becomes as loud as the end of any given track, despite any intended nuances in volume.
Many songs & albums that have been 'remastered' have also undergone this process..... but it's essentially remaking the music
not how it was supposed to sound.
Research proves that overall loudness does not sell more records, or make a tune sound more appealing. It has also proved that this craft creates ear fatigue quite quickly, meaning people get bored & lose interest in the music because their ears grow tired.
I rest my case.... end the loudness wars & bring the dynamic back into music! Er, write to your MP!
Here's a visual representation;
top, how the tune is with its natural dynamic. Below, how the tune becomes after heavy processing.