I found an interesting site that has pages and pages of Frequently Asked Questions about Led Zeppelin... and some interesting stuff was addressed. Including the rumors about plagiarism... it's kind of disappointing actually. I blame Robert Plant.
This is the site:
Led Zeppelin FAQ
Didn't Led Zeppelin copy (song title) from (blues artist)?
Yes, no, and maybe. Here's a partial list of covers, credited and otherwise, and sources. Thanks to _Wearing & Tearing_, Glen Cunliffe, Christopher Williams, _Proximity_, Hugh Jones, Bill Bratton, and Colin Harper for much of the info in this section.
"Train Kept A Rollin'" -- Written by Tiny Bradshaw, L. Mann, and H. Kay, first recorded by Bradshaw's Big Band in 1951. Rewritten as a rockabilly tune in 1956 and recorded by the Johnny Burnette Trio (whose guitarist, Paul Burlison, was an influence on Jeff Beck and inspired him to cover the tune with the Yardbirds). The Yardbirds recorded both the "original" tune and a rewritten version called "Stroll On" (the lyrics were modified to avoid copyright hassles) in Michaelangelo Antonioni's film _Blow Up_, which features the Beck/Page-era Yardbirds imitating the Who. The original version was often played live by Zeppelin, and is often mistakenly attributed to the Yardbirds, which is why it is included here.
"White Summer" -- Davey Graham's "She Moved Through The Fair."
"Babe I'm Gonna Leave You" -- Anne Bredon (a/k/a Annie Briggs) (the Joan Baez version was the one this was based on).
"You Shook Me" -- Willie Dixon, first recorded by Muddy Waters.
"I Can't Quit You Baby" -- Willie Dixon.
"Communication Breakdown" -- Eddie Cochran's "Nervous Breakdown."
"How Many More Times" -- Howlin Wolf's "How Many More Years," Albert King's "The Hunter," Zeppelin's version is lyrically related to a cover called "How Many More Times" by Gary Farr and the T-Bones (liner notes by Giorgio Gomelsky, one-time producer of The Yardbirds). Zeppelin's particular arrangement grew from the live jams on "Smokestack Lightning" that the Page-led Yardbirds used to do.
"Dazed And Confused" -- Jake Holmes, written and recorded as "Dazed & Confused." The Yardbirds covered it under the title "I'm Confused," with different lyrics. Page again changed the lyrics (which were originally about an acid trip) for the Zeppelin version. The version on the _Session Man_ album (on Archive) credited to the New Yardbirds is actually the Holmes original. Page: "I don't know about all that. I'd rather not get into it because I don't know all the circumstances. What's he got, the riff or whatever? Because Robert wrote some of the lyrics on that album. But he was only listening to...we extended it from the one that we were playing with the Yardbirds. I haven't heard Jake Holmes so I don't know what it's all about anyway. Usually my riffs are pretty damn original [laughs]. What can I say?"
"Black Mountain Side" -- traditional, Annie Briggs, Bert Jansch The main riff is almost identical to the riff Jansch uses in his song "BlackWater Side," though he cites Annie Briggs as an earlier source. Page: "I wasn't totally original on that riff. It had been done in folk clubs a lot. Annie Briggs was the first one that I heard do that riff. I was playing it as well, and then there was Bert Jansch's version." The DADGAD tuning used here and on "White Summer," "Kashmir," "Swan Song" (see the unreleased section), and "Midnight Moonlight" was supposedly invented by Davey Graham, though whether or not Page knew this is unclear.
"The Lemon Song" -- Chester Burnett (a/k/a Howlin Wolf) "Killing Floor," Robert Johnson ("squeeze my lemon" lyric). In some early concerts and on some pressings of _II_, the song was actually called "Killing Floor." ARC Music filed a suit against Zeppelin in the early 70's, which was settled out of court. Ironically, the "squeeze my lemon" lyric was lifted by Johnson as well--from Art McKay ("She Squeezed My Lemon"--1937).
"Moby Dick" -- Bobby Parker (music), Ginger Baker's "Toad" (drum solo). The song was originally entitled "The Girl I Love," which was written in 1929 by Sleepy John Estes and called "The Girl I Love, She Got Long Curly Hair." There are also some drum lines lifted intact from George Suranovich's drum solo with Arthur Lee's Love's song "Doggone."
"Whole Lotta Love" -- Willie Dixon's "You Need Love" (lyrics). Plant: "Page's riff was Page's riff. It was there before anything else. I just thought, 'well, what am I going to sing?' That was it, a nick. Now happily paid for. At the time, there was a lot of conversation about what to do. It was decided that it was so far away in time (it was in fact 7 years) and influence that...well, you only get caught when you're successful. That's the game." Willie Dixon sued Zeppelin (actually friends of his at the time) in 1985 when his daughter noticed the resemblance--though by this time, Zeppelin has sold the rights to their international catalog and knew _in advance_ of the suit, which was filed only _after_ the sale had been completed.
"Thank You" -- There is a striking chordal similarity to Traffic's "Dear Mr. Fantasy." There is an intriguing rumor that Page is actually the guitarist on the Traffic song, though no one involved has confirmed this.
"Bring It On Home" -- Written by Willie Dixon, though the Sonny Boy Williamson II version is the one which this bears a similarity to. The "Lemon Song" lawsuit also included language about this song.
"Traveling Riverside Blues" -- Johnny Winter's "Leavin' Blues" (music only), plus lyrical references to Robert Johnson, St. Louis Jimmy Oden, and Sleepy John Estes.
"Since I've Been Loving You" -- brief lyrical nod to Moby Grape's "Never."
"Bron-Y-Aur Stomp" -- intro lifted from "The Waggoner's Tale" by Bert Jansch.
"Gallows Pole" -- traditional, associated with Leadbelly. Page says that his version was based on a cover of the song by Fred Gerlach.
"Hats Off To (Roy) Harper" -- traditional, Bukka White (song entitled "Shake 'Em On Down"), also covered by Joe Lee Williams and Blind Lemon Jefferson.
"Black Dog" -- the vocal arrangement is very similar to Fleetwood Mac's "Oh Well."
"Rock And Roll" -- drawn from Little Richard's "Good Golly Miss Molly/Keep A Knockin'" (mostly the drum line).
"Stairway To Heaven" -- Possible (though unlikely) lift from "And She's Lonely" by The Chocolate Watch Band, which became the intro chords. There's really no way of knowing for sure. The solo chords are also similar to the chords of Dylan's (and Hendrix's) "All Along The Watchtower," though the chord progression is hardly uncommon and any direct influence is also unlikely. A more believable lift might be from Spirit's "Taurus," an instrumental from their _Time Circle_ album--the intro from "Stairway" is remarkably similar, and Page and Plant were certainly aware of the band.
"When The Levee Breaks" -- Memphis Minnie and Kansas Joe McCoy.
_Physical Graffiti_ -- The album cover is identical in concept and very similar in design to the cover of the Jose Feliciano album _Compartments_, including the pull-out card and the "hidden" photos.
"Custard Pie" -- Sleepy John Estes did a song entitled "Drop Down Daddy" in 1935, which seems to be the earliest source for this material. Blind Boy Fuller recorded a song entitled "I Want Some Of Your Pie" in 1939. Sonny Terry covered it with the title "Custard Pie Blues." Big Joe Williams also covered it under the title "Drop Down Mama," and his lyrics are pretty much identical to Plant's. There is also some Bukka White material in the song.
"In My Time Of Dying" -- Traditional. First recorded by Blind Willie Johnson as "Jesus Make Up My Dying Bed," which is more like the Zeppelin version than the well-known Bob Dylan cover. Plant has cited Josh White's 1933 "Jesus Make Up My Dying Bed" as the source for Zeppelin's version. A much closer version appears on the self-titled album by the Canadian band Fear Itself, whose "In My Time OF Dying" is credited to Ellen McIlwaine, the band's lead singer and slide guitarist. Besides many musical and length similarities, the Fear Itself version ends with the line, "My dying...cough."
"Boogie With Stu" -- Ritchie Valens. Page: "The jam [with Ian Stewart] turned into 'Boogie With Stu,' which was obviously a variation on 'Ooh My Head' by the late Ritchie Valens, which itself was actually a variation of Little Richard's 'Ooh My Soul.' What we tried to do was give Ritchie's mother credit, because we heard she never received any royalties from any of her son's hits, and Robert did lean on that lyric a bit. So what happens? They tried to sue us for all of the song! We had to say 'bugger off.'" The Valens song bears a strong similarity to Memphis Minnie's "I Called You This Morning."
"Nobody's Fault But Mine" -- Blind Willie Johnson (lyrics). Plant: "First of all, it's public domain because he's been dead so long, and secondly it wasn't his song in the first place--nobody knows where it comes from."
"In The Evening" -- James Carr has a song called "In the Evening, When The Sun Goes Down." The music is not similar.
"We're Gonna Groove" -- Ben E. King, James Bethea.
"Darlene" -- One line from Don McLean's "American Pie."
So is this theivery? Yes, no and maybe. ;-) They _did_ steal a few things outright--like "Dazed And Confused" (stolen by the Yardbirds, actually)--but anyone who understands the blues tradition knows that this sort of "borrowing" goes on all the time. Willie Dixon may have been more savvy about copyrights than his counterparts, but he was no stranger to plagiarism himself. Many of the "songs" Dixon copyrighted could be considered public domain. And in the end, most of Zeppelin's "lifts" were eventually paid for.
Besides, as was the case with "Traveling Riverside Blues," the Zeppelin version often bore little (if any) resemblance to the original. Page: "...Robert was supposed to change the [lyrics], and he didn't always do that--which is what brought on most of our grief." [...] "So, anyway, if there is any plagiarism, just blame Robert! (laughs)"
at either the bass playing or the organ playing. John Paul Jones kicks ass, hands down.
