Four in One (subtitled A Tribute to Thelonious Monk) is the debut album by the group Sphere featuring pianist Kenny Barron, bassist Buster Williams, and Monk's former drummer Ben Riley, and his former saxophonist Charlie Rouse.

[1][2][3] Four in One was coincidentally recorded on the day of Monk's death in 1982, though the musicians were unaware of Monk's death during the recording session and had not planned the album as a memorial tribute.

[4] In his review on AllMusic, Ron Wynn states: "Tremendous tribute effort, outstanding versions of Monk classics.

Top-flight Monk repertory effort.

"[5] All compositions by Thelonious Monk.