The covers album was, at one time, almost an obligatory part of an artist’s career arc. From Bob Dylan to Bowie, every major icon has lined up to pay (sometimes dubious) ‘tribute’ to their heroes. For someone who wore her influences so boldly on her sleeve from the off, it’s something of a mystery as to why it’s taken Patti Smith so long to do it. Even more of a mystery to her fans may be her choice of songs to cover. Twelve - in turns revelatory, misjudged and even, in places, banal - is not all that it seems…

The entry point of Hendrix’s “Are You Experienced?” is a fine way to kick off proceedings; all military snare and raga madness. Smith’s reading of “Hey Joe” in all its three-chord punkiness always made sense, but this psychedelic musing is one of the album’s lightbulb-over-the-head moments. Just as Television (whose Tom Verlaine makes an obligatory appearance here) used to joke that they split up on a full moon because Moby Grape did, Smith’s position as elder stateswoman of punk always meant that her vintage was just as much 67 as 77. Nearly half of Twelve’s tracks stem from the summer of love or its neighbourhood. And it’s these tracks that work best.

Jefferson Airplane’s “White Rabbit”, with spooky spoken intro, pays homage to Smith’s lineage as a descendant of Grace Slick’s woman-as-rock-icon while her rendition of The Beatles' “Within You Without You” sounds like it could have been written for her. Likewise Jimbo Morrison’s “Soul Kitchen”: It seems that the hippy within never died, and thank goodness, because Patti’s other choices can be a little challenging.

A reading of ''Gimme Shelter'' is surprisingly weak-kneed considering the fact that she carved a niche all of her own in the territory between Jagger and Dylan. And while Bob’s “Changing Of The Guards” (from the often overlooked Street Legal) is a little leftfield the versions of Tears For Fears’ “Everybody Wants To Rule The World” and Paul Simon’s “Boy In The Bubble'’ are downright perverse. If their sentiments have a universality, they’re still essentially songs that should remain in their original states. The jury also remains out on her bluegrass appropriation of “Smells Like Teen Spirit”.

So, a very mixed bag indeed which is a real shame as, when she hits the right territory, she really gives us an insight into her roots and also demonstrates a sensitivity that’s impossible to resist. Twelve may have to remain an oddity in her canon, destined for selective downloading rather than a fully-formed experience.