Dimensions & Extensions is an album by American saxophonist Sam Rivers recorded in 1967 but not released on the Blue Note label until 1986 with the original catalogue number and the intended cover artwork. It was originally scheduled for issue in 1967, but held back from release until 1975, when the tracks appeared as part of the double LP set, Involution (1976, BN-LA 453-H2), which combined them with tracks recorded under Andrew Hill's leadership that would eventually see release as Change.