Critics thought the pairing of Gerry Mulligan and Thelonious Monk a strange one when this 1957 session was originally released, Mulligan's light baritone saxophone strongly identified with the cool school and Monk's percussive piano, fractured rhythms, and dissonant tunes the last word in bop. It's an interesting combination, though, with Mulligan's melodic focus actually working fairly well with Monk and his regular band, drummer Shadow Wilson and bassist Wilbur Ware. Common roots in swing are apparent on Mulligan's "Decidedly," a variant of "Undecided," while the baritonist acquits himself well on some of Monk's best-known tunes. Monk was at his peak as a player in 1957--working steadily for the first time in years in a long tenure at the Five Spot--and it shows everywhere here, including the splashing chords and asymmetrical runs of "Sweet and Lovely." Ware, one of the most significant bassists in jazz history, is a perfect accompanist and as commanding a soloist as Mulligan or Monk, using subtle rhythmic shifts and double stops in an almost minimalist way. The alternate takes of several tunes are genuinely different approaches to the material, revealing just how spontaneous the meeting was.