I listened to the first disc of Live at the BBC to-day. Introducing "Lucille," Brian Matthew - the presenter - says, "The Beatles, with Paul McCartney paying tribute to the Everlys with 'Lucille.'" It struck me as a bit odd that it's the Everly Brothers' version of "Lucille" that's mentioned. On the second disc of Live at the BBC, the Beatles do perform the Everlys' "So How Come (No One Loves Me)," but it seems to me that Little Richard, who did the original version of "Lucille," was a greater influence. The Beatles covered a number of his songs: "Ooh! My Soul" on the BBC (which is also on Live at the BBC), "Long Tall Sally" (with a instrumental quotation of "The Girl Can't Help It") on the Long Tall Sally EP, and "Kansas City/Hey-Hey-Hey-Hey" on Beatles for Sale.
I compared four recordings of "Lucille": Little Richard's original, the Everly Brothers' cover, and two versions that the Beatles did on the BBC (one on Live at the BBC and the other on On Air - Live at the BBC, Vol. 2). Little Richard's is in C major, as are the two versions by the Beatles, but the Everlys' is in G major. As far as the key goes, it does seem like their version of "Lucille" is based more on Little Richard's than the Everlys'.
