History: Dave Navarro leaving the band must have let loose a lot of pent up creative energy they wanted to disperse that they hadn't been able to since John Frusciante had departed the band after Blood Sugar Sex Magik. The album seems to emerge with a lot more maturity than even that album, and it channels sounds that sound more intentional. It would spawn many hit singles as well including "Californication" and the one I remember most clearly, "Scar Tissue".
Vocals: Anthony Keidis are very noticeable whether he is singing fast, or in a more serious tone. While I can hear the appeal of faster tracks like "Parallel Universe" I'm more into the tracks where not only the instrumentals slow down a bit, but also the vocals. Some of the favorite tracks where I thought the vocals were some of the highlights were "Around the World" or "Otherside". There seems to be a lot more burst of emotion throughout as well. You can't forget "Scar Tissue" though, which features some of the most impressive vocals because without the little emphasis on certain words you wouldn't have near as memorable a song that stuck with you after listening, which is also why it was such a memorable single.
Instrumentals: I assume that most fans of Red Hot Chili Peppers were very glad to have the guitar work of Frusciante back. While the various other musicians are good the other unique signature of Red Hot Chili Peppers is the way the guitar sounds. With the darker themes on the album the guitar still has a more upbeat vibe that just doesn't quite match the lyrical content of what ranges from drugs to suicide. For the listener it provides some introspective thoughts while also not getting us down in the dumps listening to the album.
Did I hear any tunes from this album prior to listening?: I was vaguely familiar with this album before listening, but this isn't one of the albums I had listened to as I had other albums from the band. It lives up to expectations though from the one single I had heard, "Scar Tissue". There were many songs that kept catching my attention on the album, to be honest though I still don't prefer the faster ones though and remain a fan of the slower tunes.