It still puzzles me why this album is so criminally ignored, especially in direct comparison to 'AFTERMATH' which is considered a classic by critics. There isn't a duff track on the album (how many other Stones albums can you truly say that about? Maybe 'STICKY FINGERS'?) which is completely written by Jagger/ Richards.
Perhaps the most striking difference when compared to most Stones albums is that it is far less rock/ rhythmn & blues orientated; instead its an album chock full of melodic pop songs. Lyrically it still features the 'poison pen' approach that the Stones have always been good at but with a new found musical awareness (check out the waltz time accordian driven 'Backstreet Girl' or psych-pop of 'Yesterday's Papers').
This perhaps is the key to the success of the album, as the music goes into Dylan terrority ('Who's Been Sleeping Here?'),vaudeville ('Cool, Calm, Collected'),psychedelia ('Please Go Home') and Dixie Jazz ('Something Happened To Me Yesterday'). In addition the songwriting is very strong as they rely less on riffs and more on melody and harmony. On several songs Jagger seems to really attempt to stretch his vocal range and its actually quite appealing.
The Stones would continue in this "softer" direction with the even more psychedelic (and indulgent) 'THEIR SATANIC MAJESTIES REQUEST', before returning to their roots with 'BEGGARS BANQUET'. They haven't really strayed too far from their core sound since. Given the fact that tracks from this album are rarely found on Stones comps it makes getting this album all the more essential.