It was really all rock bands, especially Led Zepplin, Rolling Stones, etc. It was more about the rock lifestyle than any one band in particular.
A number of Spinal Tap's songs cover identical subjects to renowned songs by other bands. For example, "Gimme Some Money" is similar to the Beatles' "Money (That's What I Want)" (and its appearance in This Is Spinal Tap is a parody of the Beatles' famous appearance on the Ed Sullivan Show) and "Big Bottom" is similar to Queen's "Fat Bottomed Girls." The subtext is that Spinal Tap is so unoriginal they do not just imitate other bands' sounds, but their subject matter as well. "Big Bottom" features three bass guitars.
Derek Small's on-stage incident where he is trapped within a plastic clamshell is a parody of the same incident at a Yes concert where drummer Alan White was trapped in a similar prop and had to be cut free. 
"The Drummer's Curse," where every drummer that plays with the band dies in mysterious or inexplicable circumstances is based on the Grateful Dead's 4 dead keyboard players (from alcoholism, a car crash, drug overdose and suicide) and/or the Allman Brothers Band's 3 dead bass players (mortorcycle crash, Agent Orange-induced cancer, and unknown circumstances). However, in a tragic case of life imitating art, the rock band Toto's former drummer Jeff Porcaro died from an allergic reaction to a pesticide he was using in his
Tufnel's use of a violin in some guitar solos is based on Jimmy Page's occasional use of a violin bow in Led Zeppelin gigs.
Robert Plant of Led Zeppelin was asked in an interview by Rolling Stone what scenes in Spinal Tap hit home. He replied: "Getting lost on the way to the stage. That was us, playing in Baltimore. It took twenty-five minutes to do the hundred yards from our Holiday Inn through the kitchen to the arena."
On a concert in the late 80's, the members of Kiss got lost on their way to the stage, just like Spın̈al Tap did in the film This Is Spinal Tap
Nigel Tufnel is based upon Jeff Beck and Eric Clapton, who were both members of The Yardbirds. Nigel's physical appearance resembles Beck, and his name ("Nigel Tufnel") is a reference to Clapton.