Thelonious Monk's fourth album for Riverside stands between two of his most celebrated group recordings, following Brilliant Corners and preceding Monk's Music, but in itself it is of notable importance for several reasons. This was Monk's first recorded work in the watershed year of 1957, in which he broke through to major recognition. It was his first (almost) entirely solo album. And it includes at least two performances of lasting significance: the unaccompanied version of his classic "'Round Midnight", and the one exception to the album's solo format, "Monk's Mood", on which he is joined by Wilbur Ware and–for the very first time–John Coltrane.