The departure of "non-musician" rhythm section Paul "Bonehead" Arthurs (rhythm guitar) and Paul "Guigsy" McGuigan (bass) after Be Here Now is the real turning point, not the Gallagher feud. Their simple, locked-in, groovy foundation allowed the Gallaghers' chaos to float on top. Their replacements (Gem Archer, Andy Bell) were technically superior but turned Oasis into a more competent, less magical rock band.
If the 1990s had a soundtrack in the UK, the guitars were definitely loud, the attitude was Electric, and the brothers were fighting. We are, of course, talking about . albums by oasis