Songfacts®:

• Long before Nike came up with "Just Do It," B.T. Express delivered the funk classic "Do It ('Til You're Satisfied)." The groove carries along a simple but profound message: do what works for you, and do it 'til you're satisfied.
• The song was written by Billy Nichols, who had written Millie Jackson's hit "Ask Me What You Want" and had toured with both Marvin Gaye and The Spinners playing saxophone and guitar. He wrote it to motivate himself and others.
  
  "I wanted anytime in my life to look at that and say, 'How could I not be motivated?'" he said in the Billboard Book Of #1 R&B Hits.
• This was the first single for B.T. Express, a seven-member group based in New York City that included a female vocalist, Barbara Joyce Lomas. Four other guys in the group also sang, giving them multi-pronged vocal sound like Sly & the Family Stone. With six instrumentalist, they could add lots of layers. "Do It ('Til You're Satisfied)" includes guitar, bass, organ, drums, flute and saxophone.
• The full version on the album runs 5:52, with an organ solo and some seductive moaning in the middle. The single edit is cut down to 3:31.
• Billy Nichols started with the groove when he wrote this song, and that groove was so good he just wanted the line "do it ('til you're satisfied)" to repeat throughout the song as the entire lyric. He decided to add some verses and made a demo that the group used as a guide, with Nichols present at the session. He says he was asked to join the group but turned them down because he didn't want to tour.
• The B.T. stands for "Brooklyn Trucking." "Express" was a trendy word for band names around this time, used not only by the bubblegum group Ohio Express, but also by Liz Damon's Orient Express, The Electric Express, and various other groups with train-themed names.
• "Do It ('Til You're Satisfied)" was a #1 R&B hit and spent two weeks at #2 on the Hot 100, held off first by John Lennon's "Whatever Gets You Thru The Night," then by Billy Swan's "I Can Help."
  
  The group followed up with the song "Express," which they wrote themselves and went to #4. Billy Nichols wrote another song for them called "Can't Stop Groovin' Now, Wanna Do It Some More," which went to #51 in 1976.
• Many songs have sampled "Do It ('Til You're Satisfied)," most notably the 2001 Ludacris hit "Area Codes" and the 2006 Beyoncé song "Deja Vu."
• This was used in the 2013 video game Grand Theft Auto V, and also in these movies:
  
  Invincible (2006)
  The Dukes of Hazzard (2005)
  The Hot Chick (2002)
  Serving Sara (2002)
  Bad Boy (2002)
  The Stöned Age (1994)
  Carlito's Way (1993)