To say that Vol 4 was the beginning of the end for Sabbath, the start of the long downward spiral into break ups and infighting, as some have commented is a bit of an overstatement.
The year was 1972. The band had only been going as a professional unit, with albums under it belt for 2 years ! If anything, Vol 4 consolidated everything that the band had put into previous efforts, tweaked the problems and brought the good stuff to the fore.
If you want to hear it start to go wrong, or at least go awry, buy `Sabotage'.
Vol 4 is in my opinion a monster of a record. From the opening distraught guitars of Wheels of Confusion, to the last notes of Under the Sun, this album shows Sabbath doing what they do best, experimenting with sound and pulling it off.
Sure the inclusion of tracks like `FX' and `Changes', are all a bit unnecessary, the former track being regarded by Tommy Iommi now as a complete waste of time.
Vol 4 has after all some of Sabbath's greatest live songs on it. Supernaught, not only a distinctly "Sabbath track" but one of rocks all time best tunes. Snowblind, again, shows off Sabbath's knack of going from pretty mid paced, melancholic ramblings, to all out vehement aggressive rock. And that's what makes them great.
Iommi's crushing guitar riffs, Butler's bass punching the music out of the speakers, bill Wards drumming, strangely furious in places, in others almost stoned. And of course Ozzy's strangled, some times sorrowful, sometimes violent vocals.
The riffs on tracks like Supernaught and St Vitus Dance just reaffirm why Sabbath are the true granddaddies of modern metal. With songs like the ones mentioned above, and Tommorows Dream as another great example, its very hard not to want to tap your foot or nod your head to the infectious "groove" and thick slab riffs.
Not Sabbath's heaviest album featuring Ozzy, that accolade goes to `Master of Reality', and maybe not their most dynamic or spontaneous effort, (Their debut and Paranoid both pip it) but certainly an amazing collection of songs, certainly 100% Sabbath.