Question: Which Tax Attorney is recognized as an expert of an English rock band who's members include Paul McCartney and Ringo Starr?

Context paragraphs:
The Beatles: The Beatles were an English rock band formed in Liverpool in 1960.  With members John Lennon, Paul McCartney, George Harrison and Ringo Starr, they became widely regarded as the foremost and most influential act of the rock era.  Rooted in skiffle, beat and 1950s rock and roll, the Beatles later experimented with several musical styles, ranging from pop ballads and Indian music to psychedelia and hard rock, often incorporating classical elements and unconventional recording techniques in innovative ways.  In 1963 their enormous popularity first emerged as "Beatlemania", and as the group's music grew in sophistication in subsequent years, led by primary songwriters Lennon and McCartney, they came to be perceived as an embodiment of the ideals shared by the counterculture of the 1960s.

Six O'Clock: "Six O'Clock" is a song by English musician Ringo Starr from his 1973 album "Ringo".  It was written by Starr's former Beatles bandmate Paul McCartney and the latter's wife, Linda, who also participated in the recording of the song.  The presence of McCartney on the track marked the first time that he and Starr had worked together since the Beatles' break-up in 1970, reflecting an easing of the tensions that had existed between the two musicians for much of that period.

Early 1970: "Early 1970" is a song by English musician Ringo Starr, released in April 1971 as the B-side to his hit single "It Don't Come Easy".  It was inspired by the break-up of the Beatles and documents Starr's relationship with his former bandmates, John Lennon, Paul McCartney and George Harrison.  The lyrics to the verses comment in turn on each of the ex-Beatles' personal lives and the likelihood of each of them making music with Starr again; in the final verse, Starr acknowledges his musical limitations before expressing the hope that all the former Beatles will play together in the future.  Commentators have variously described "Early 1970" as "a rough draft of a peace treaty" and "a disarming open letter" from Starr to Lennon, McCartney and Harrison.

Give My Regards to Broad Street (film): Give My Regards to Broad Street is a 1984 British musical drama film directed by Peter Webb, which starred Paul McCartney, Bryan Brown and Ringo Starr.  The film covers a fictional day in the life of Paul McCartney, who wrote the film for the screen, and McCartney, Starr and Linda McCartney all appeared as themselves.  Despite "Give My Regards to Broad Street" being unsuccessful in the box office financially and critically, its soundtrack album sold well.  The title is a take on George M. Cohan's classic show tune "Give My Regards to Broadway" which made reference to London's Broad Street railway station, which would close in 1986.

Cultural impact of the Beatles: The Beatles were an English rock band, formed in Liverpool in 1960.  With members John Lennon, Paul McCartney, George Harrison and Ringo Starr, they became widely regarded as the foremost and most influential act of the rock era.  In the early 1960s, their enormous popularity first emerged as "Beatlemania", but as the group's music grew in sophistication, led by primary songwriters Lennon and McCartney, they came to be perceived as an embodiment of the ideals shared by the counterculture of the 1960s.

You and Me (Babe): "You and Me (Babe)" is a song by English musician Ringo Starr, released as the final track on his 1973 album "Ringo".  Starr's fellow ex-Beatle George Harrison wrote the song along with Mal Evans, the Beatles' longtime aide and a personal assistant to Starr during the making of "Ringo".  The track serves as a farewell from Starr to his audience in the manner of a show-closing finale, by lyrically referring to the completion of the album.  During the extended fadeout, Starr delivers a spoken message in which he thanks the musicians and studio personnel who helped with the recording of "Ringo" – among them, Harrison, John Lennon and Paul McCartney, and his producer, Richard Perry.

Bruce Spizer: David "Bruce" Spizer (born July 2, 1955) is a tax attorney in New Orleans, Louisiana, who is also recognized as an expert on The Beatles.  He has published eight books, and is frequently quoted as an authority on the history of the band and its recordings.

Sentimental Journey (Ringo Starr album): Sentimental Journey is the debut studio album by English rock musician and former Beatles drummer Ringo Starr, released in 1970, as the band was splintering apart.  Although Starr was the third member of the group to issue solo work (after George Harrison and John Lennon), "Sentimental Journey" is notable for being the first non-avant-garde studio album by a member of the band, in light of the experimental, soundtrack or live releases his aforementioned bandmates had already released.  Paul McCartney's debut, "McCartney", would follow three weeks after "Sentimental Journey"'s release.  Recording of the album was completed in early March 1970, with "Sentimental Journey" being rushed out a few weeks later to avoid clashing in the shops with the Beatles' impending final album "Let It Be" in May.

4: John Paul George Ringo: 4: John Paul George Ringo is a digital extended play compilation released on 23 September 2014, as a free download by the iTunes Store.  It features one solo song by each former member of the Beatles: John Lennon, Paul McCartney, George Harrison and Ringo Starr.  It is the first official release to bring together their solo material (though two Starr solo albums, "Ringo" and "Ringo's Rotogravure", and the 1996 Carl Perkins album "Go Cat Go! " featured contributions from each of the four).

A Sideman's Journey: A Sideman's Journey is the first solo album by German musician and artist Klaus Voormann, released in July 2009.  Voormann is best known as the creator of the cover art for The Beatles' album "Revolver" as well as for being a much-in-demand session musician during the 1970s.  He played bass on a large number of well-known albums by ex-Beatles John Lennon, George Harrison and Ringo Starr − including "All Things Must Pass", "Imagine" and "The Concert for Bangladesh" − and by artists such as Harry Nilsson, Doris Troy, Lou Reed, Gary Wright, Carly Simon and Randy Newman.  Before then, Voormann had been a member of the 1960s pop group Manfred Mann.  "A Sideman's Journey" is notable for including performances by Paul McCartney, Ringo Starr and Yusuf Islam (Cat Stevens), among others.

Supporting paragraphs: Bruce Spizer The Beatles
Answer: David "Bruce" Spizer