"dark-tinged Krishna folk-rock". The recurrent lyrical themes are Harrison's spiritual quest, as it would be throughout his solo career, and friendship, particularly the failure of relationships among the Beatles. Music journalist Jim Irvin says that Harrison sings of "deep love – for his faith, for life and the people around him". He adds that the songs are performed with "tension and urgency" as if "the whole thing is happening on the edge of a canyon, an abyss into which the '60s is about to topple". Apple Jam On the original LP's third disc, titled Apple Jam, four of the five tracks – "Out of the Blue", "Plug Me In", "I Remember Jeep" and "Thanks for the Pepperoni" – are improvised instrumentals built around minimal chord changes, or in the case of "Out of the Blue", a single-chord riff. The title for "I Remember Jeep" originated from the name of Clapton's dog, Jeep, and "Thanks for the Pepperoni" came from a line on a Lenny Bruce comedy album. In a December 2000 interview with Billboard magazine, Harrison explained: "For the jams, I didn't want to just throw [them] in the cupboard, and yet at the same time it wasn't part of the record; that's why I put it on a separate label to go in the package as a kind of bonus." The only vocal selection on Apple Jam is "It's Johnny's Birthday", sung to the tune of Cliff Richard's 1968 hit "Congratulations", and recorded as a gift from Harrison to Lennon to mark the latter's 30th birthday. Like all the "free" tracks on the bonus disc, "It's Johnny's Birthday" carried a Harrison songwriting credit on the original UK release of All Things Must Pass, while on the first US copies, the only songwriting information on the record's face labels was the standard inclusion of a performing rights organisation, BMI. In December 1970, "Congratulations" songwriters Bill Martin and Phil Coulter claimed royalties, with the result that the composer's credit for Harrison's track was swiftly changed to acknowledge Martin and Coulter. Demo tracks and outtakes Aside from the seventeen songs issued on discs one and two of the original album, Harrison recorded at least twenty other songs – either in demo form for Spector's benefit, just before recording got officially under way in late May, or as outtakes from the sessions. In a 1992 interview, Harrison commented on the volume of material: