[5] He was raised in the Jewish faith; his mother volunteered with local charities, and donated to Hadassah Women's Zionist Organization of America.

[7] As a child, Shaffer took piano lessons, and in his teenage years played the organ in a band called Fabulous Fugitives with his schoolmates in Thunder Bay.

Educated at the University of Toronto, he began playing with jazz guitarist Tisziji Muñoz, performing in bands around the bars there, where he found an interest in musicals, and completed his studies, with a Bachelor of Arts degree in sociology in 1971.

[8] Shaffer appears briefly, playing an organ at an outdoor wedding, in North of Superior (1971), an early IMAX documentary shot in northern Ontario.

Shaffer also regularly appeared in the show's sketches, notably as the pianist for Bill Murray's Nick the Lounge Singer character, and as Don Kirshner.

[citation needed] Shaffer left SNL in 1977 for a few months to co-star with Greg Evigan in A Year at the Top, a short-lived CBS sitcom in which Shaffer and Evigan play two musicians from Idaho who relocate to Hollywood, where they are regularly tempted by a famous promoter (who is actually the devil's son), played by Gabriel Dell, to sell their souls in exchange for a year of stardom.

It not only escaped the censors in the live broadcast and the West Coast taped airing, but also reappeared in the summer rerun, and even in the syndicated versions of the show for several years.

[citation needed] Shaffer, along with executive producer Lorne Michaels, the entire cast, most of the writing staff, and several other band mates, left the show at the end of the season, after five years.

[15] In February 2015, Shaffer appeared on the 40th-anniversary special of SNL, playing music to Bill Murray's lounge-singer character, a love song from the movie Jaws.

Letterman consistently maintained that the show's switch to CBS was because NBC "caught Paul stealing pens" or some other trivial reason.

Finding none, he remembered his and Letterman's shared love for the sort of music produced at the Muscle Shoals Sound Studio in Sheffield, Alabama, describing it as "the honesty you hear, the southern soul feeling".

Shaffer has also recorded with a wide range of artists, including Donald Fagen, Ronnie Wood, Grand Funk Railroad, Diana Ross, B.B.

King, Asleep at the Wheel, Cyndi Lauper, Carl Perkins, Yoko Ono, Blues Traveler, Jeff Healey, Cher, Barry Manilow, Chicago, Luba, Robert Burns, George Clinton, Bootsy Collins, Nina Hagen, Robert Plant, Peter Criss, Scandal, Brian Wilson, Late Show regular Warren Zevon, jazz trumpeters Miles Davis and Lew Soloff, jazz saxophonist Lou Marini, and bluegrass legend Earl Scruggs.

Shaffer also served as musical director for Fats Domino and Friends, a Cinemax special that included Ray Charles, Jerry Lee Lewis, and Ron Wood.

[26] Shaffer has appeared in a number of motion pictures over the years, including a small role (Artie Fufkin of Polymer Records) in Rob Reiner's This Is Spinal Tap, Blues Brothers 2000, a scene with Miles Davis in the Bill Murray film Scrooged, and as a passenger in John Travolta's taxicab in Look Who's Talking Too.

The show lasted 13 episodes and featured celebrity judges including Kevin Bacon, Nile Rodgers, Cyndi Lauper, and Ace Frehley.

Shaffer served as musical director for 2001's The Concert for New York City, and accompanied Adam Sandler's "Opera Man" sketch and the Backstreet Boys' "Quit Playing Games (with My Heart)".

In 2002, he hosted the infamous Friars Club Roast of Chevy Chase on Comedy Central in which the presenters' insults directed at the comedian were so vicious, Shaffer reportedly had to console him afterwards.

[35] In 2008, Shaffer made a cameo appearance at the beginning of the Law & Order: Criminal Intent season-seven episode "Vanishing Act".

[41] In 2005, along with Steven Van Zandt, he organized a benefit for Mike Smith (formerly of The Dave Clark Five), who had suffered a paralysing fall at his home in Spain.

[2] In May 2015, the Ride of Fame honoured Shaffer with a double-decker sightseeing bus in New York City to commemorate his long run as the leader of the CBS Orchestra for the Late Show with David Letterman.