Lou's Blues is a blues composition by alto saxophonist Lou Donaldson, one of the original tunes from his early career as a Blue Note Records artist in the 1950s. The piece is a straightforward swinging blues in the hard bop idiom, with a melody that emphasizes Donaldson's signature soulful, blues-drenched phrasing over a standard twelve-bar blues progression. The harmony follows classic blues changes without elaborate substitutions, and the moderate swing tempo makes it an accessible vehicle for improvisation that prioritizes groove and feeling over harmonic complexity. Donaldson composed the tune during the period when he was transitioning from his early Charlie Parker-influenced bebop style toward the earthier, more blues-centered approach that would define his mature voice on records like Blues Walk. The tune was performed live by the Art Blakey Quintet at Birdland in February 1954, with Clifford Brown on trumpet, Horace Silver on piano, Curly Russell on bass, and Blakey on drums, and appears on A Night at Birdland Vol. 2. Donaldson's studio recording was released on Quartet/Quintet/Sextet (Blue Note, 1957), produced by Alfred Lion and engineered by Rudy Van Gelder, with Blue Mitchell on trumpet and Horace Parlan on piano. He returned to the tune decades later on Live in Bologna (Timeless, 1984), extending the performance in a quartet setting. Lou's Blues remains primarily associated with Donaldson's own recordings and has not been widely covered by other artists, sitting as a deep cut in the hard bop blues repertoire.