Well you must know about this one right? I dig the psychedelic vibe of the Purple version but can understand why the Cream version is more popular. Is it the only old blues the Purp covered?
That was credited to Skip James even on their first album (they weren't Led Zep after all), but save for the intro, they are basically aping the Cream arrangement. DP's debut was recorded so quickly after their foundation they were at loss for material, hence the many covers. That psychedelic vibe of the first album (and the two albums that followed it) were
quaintly out of touch with musical styles upon release in 1968/69, psychedelia had peaked already and was regarded especially in the UK as yesterday's flavor (there is a reason why Hush was a big hit in the US, but didn't even dent the charts in the UK and Europe).
Purple always had a blues ingredient, among their live material were covers of Going Down and Rock Me Baby, a lot of their songs followed blues patterns: Wring That Neck/Hard Road, Why Didn't Rosemary, Demon's Eye, Lazy, Place In Line. Prior to DP, Jon Lord had basically done nothing else but play in British blues outfits, most prominently in The Artwoods.
It never left him, shortly before his untimely death he was part of a blues project with other Brit blues players from the British Blues Invasion period (or thereabouts). Classical music and the Blues were his main influences.
